Tag: 100-200

Characterization of the volatile profile of Brazilian Merlot wines through comprehensive two dimensional gas chromatography time-of-flight mass spectrometric detection was written by Welke, Juliane Elisa;Manfroi, Vitor;Zanus, Mauro;Lazarotto, Marcelo;Alcaraz Zini, Claudia. And the article was included in Journal of Chromatography A in 2012.COA of Formula: C7H14O3 The following contents are mentioned in the article:

Wine aroma is an important characteristic and may be related to certain specific parameters, such as raw material and production process. The complexity of Merlot wine aroma was considered suitable for comprehensive two-dimensional gas chromatog. (GC 脳 GC), as this technique offers superior performance when compared to one-dimensional gas chromatog. (1D-GC). The profile of volatile compounds of Merlot wine was, for the first time, qual. analyzed by HS-SPME-GC 脳 GC with a time-of-flight mass spectrometric detector (TOFMS), resulting in 179 compounds tentatively identified by comparison of exptl. GC 脳 GC retention indexes and mass spectra with literature 1D-GC data and 155 compounds tentatively identified only by mass spectra comparison. A set of GC 脳 GC exptl. retention indexes was also, for the first time, presented for a specific inverse set of columns. Esters were present in higher number (94), followed by alcs. (80), ketones (29), acids (29), aldehydes (23), terpenes (23), lactones (16), furans (14), sulfur compounds (9), phenols (7), pyrroles (5), C13-norisoprenoids (3), and pyrans (2). GC 脳 GC/TOFMS parameters were improved and optimal conditions were: a polar (polyethylene glycol)/medium polar (50% Ph 50% di-Me arylene siloxane) column set, oven temperature offset of 10 掳C, 7 s as modulation period and 1.4 s of hot pulse duration. Co-elutions came up to 138 compounds in ¹D and some of them were resolved in ²D. Among the co-eluted compounds, thirty-three volatiles co-eluted in both ¹D and ²D and their tentative identification was possible only due to spectral deconvolution. Some compounds that might have important contribution to aroma notes were included in these superimposed peaks. Structurally organized distribution of compounds in the 2D space was observed for esters, aldehydes and ketones, alcs., thiols, lactones, acids and also inside subgroups, as occurred with esters and alcs. The Fischer Ratio was useful for establishing the analytes responsible for the main differences between Merlot and non-Merlot wines. Differentiation among Merlot wines and wines of other grape varieties were mainly perceived through the following components: Et dodecanoate, 1-hexanol, Et nonanoate, Et hexanoate, Et decanoate, dehydro-2-methyl-3(2H)thiophenone, 3-Me butanoic acid, Et tetradecanoate, Me octanoate, 1,4 butanediol, and 6-methyloctan-1-ol. This study involved multiple reactions and reactants, such as Ethyl 3-ethoxypropanoate (cas: 763-69-9COA of Formula: C7H14O3).

Ethyl 3-ethoxypropanoate (cas: 763-69-9) belongs to esters. Esters are widespread in nature and are widely used in industry. In nature, fats are in general triesters derived from glycerol and fatty acids. Esters are responsible for the aroma of many fruits. Esterification is the general name for a chemical reaction in which two reactants (typically an alcohol and an acid) form an ester as the reaction product. Esters are common in organic chemistry and biological materials.COA of Formula: C7H14O3

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

HS-SPME-GC-MS coupled with OPLS-DA to analyze effects of extraction methods on volatile aroma compounds of avocado oil was written by Ouyang, Hong-jun;Liu, Yi-jun;Yuan, Yuan;Jing, Wei;Zhang, Li;Li, Ji-hua. And the article was included in Nanfang Nongye Xuebao in 2021.Application of 112-14-1 The following contents are mentioned in the article:

Objective: The effects of three methods (namely, hot pressing method, supercritical extraction method and aqueous extraction method on the volatile aroma compounds in avocado oil were clarified, which provided data support for the extraction and development of avocado oil. Method: Headspace solid phase microextraction-gas chromatog.-mass spectrometry (HS-SPME-GC-MS) coupled with orthogonal partial least squares discrimination anal. (OPLS-DA) were used to identify the volatile aromas of avocado oil extracted by hot pressing method, supercritical carbon dioxide extraction and water extraction method, and to distinguish between groups and analyze the overall difference. Result: In total, 80 kinds of volatile aroma compounds were identified from avocado oil extracted by the three methods, and there were 40, 40 and 45 volatile aroma compounds in the oil extracted by hot pressing method, supercritical carbon dioxide extraction and water extraction method resp. They were mainly hydrocarbons, aldehydes, acids and alcs. There were 17 kinds of hydrocarbons, 5 kinds of aldehydes, 8 kinds of alcs. and 3 kinds of acids in hot pressing method, accounting for 45.68%, 3.31%, 9.39% and 21.65%, resp. There were 13 kinds of hydrocarbons, 14 kinds of aldehydes, 8 kinds of alcs., and 2 kinds of acids were identified in water extraction method, accounting for 28.87%, 26.42%, 15.92%, 19.53%. There were 21 kinds of hydrocarbons, 9 kinds of aldehydes, 4 kinds of alcs., 1 kinds of acids in supercritical carbon dioxide extraction method, accounting for 42.99%, 12.77%, 7.75%, 20.23%, resp. OPLS-DA method was used to analyze the volatile aroma compounds produced by three avocado oil samples, which could effectively distinguish avocado oil samples obtained by three methods. There were 56 kinds of symbolic difference compounds existed in three samples, and 13 kinds of special components in supercritical carbon dioxide extraction, such as decane and toluene, and 16 kinds of special components in aqueous method, such as 2-heptene-1-ol and 1-octene-3-ol, and 18 kinds of common components in three methods, such as hexanal, 2-heptenal. Conclusion: The differences of volatile aroma compounds are analyzed by HS-SPME-GC-MS combined with OPLS-DA, and the potential compounds that form differences are screened out. This method can be used to quickly identify the extraction methods of avocado oil. This study involved multiple reactions and reactants, such as Octyl acetate (cas: 112-14-1Application of 112-14-1).

Octyl acetate (cas: 112-14-1) belongs to esters. Esters are also usually derived from carboxylic acids. It may also be obtained by reaction of acid anhydride or acid halides with alcohols or by the reaction of salts of carboxylic acids with alkyl halides. Because of their lack of hydrogen-bond-donating ability, esters do not self-associate. Consequently, esters are more volatile than carboxylic acids of similar molecular weight.Application of 112-14-1

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

A comparative study of volatile flavor components in four types of zaoyu using comprehensive two-dimensional gas chromatography in combination with time-of-flight mass spectrometry was written by Chen, Zhipeng;Tang, Haiqing;Ou, Changrong;Xie, Cheng;Cao, Jinxuan;Zhang, Xin. And the article was included in Journal of Food Processing and Preservation in 2021.Product Details of 2198-61-0 The following contents are mentioned in the article:

Volatiles of four zaoyu (Chinese traditional fermented fish) products prepared from different species of marine fish were analyzed by headspace solid-phase micro-extraction (HS-SPME) and comprehensive two-dimensional gas chromatog. in combination with time-of-flight mass spectrometry (GC 脳 GC/TOFMS). First, a 50/30螠 m DVB/CAR/PDMS was used and the influence of several parameters on the efficiency of HS-SPME such as extraction temperature, time, salting-out effect, and stirring were optimized, odor activity values (OAVs) of volatile compounds were computed based on the threshold values of aroma constituents; the characteristic volatiles and their odor characteristics of the four zaoyu were investigated. The results demonstrated that the most effective extraction of the analytes was obtained with a 40 min extraction at 50掳C with the addition of 20% NaCl and stirring at 300 r/min. Under these conditions, a total of 288 volatile components were tentatively identified based on mass spectra and comparison of linear retention indexes in the four zaoyu products. Authenticated compounds included aldehydes, esters, alcs., ketones, furans, lactones, nitrogen compounds, sulfur compounds, terpenes, phenols, etc. Among the identified types of volatile compounds, the number of esters is the largest, whereas the content of aldehydes is the highest. The results of OAVs comparisons proved that both aldehydes and esters provided the most significant contribution to the aromas of zaoyu, and each zaoyu product had its own unique active flavor components. Moreover, the OAVs of active flavor compounds common to the four examined zaoyu varied significantly. Our results substantiated that GC 脳 GC/TOFMS could provide a robust tech. means to understand the flavor characteristics of zaoyu and allow us to better evaluate and improve the flavor quality of the products with complex food matrix like zaoyu. The method present in this research is suitable to characterize the volatile constituents of aquatic products, and could also be used for component characterization of similar complex samples such as fermented fish and foods. Understanding the key aroma compounds of fermented fish and its formation mechanism could provide a guide of process optimization and flavor regulation, contributing to further studies related to volatile compounds in the field of food flavor anal. This study involved multiple reactions and reactants, such as Isopentyl hexanoate (cas: 2198-61-0Product Details of 2198-61-0).

Isopentyl hexanoate (cas: 2198-61-0) belongs to esters. Esters typically have a pleasant smell; those of low molecular weight are commonly used as fragrances and are found in essential oils and pheromones. Esterification is the general name for a chemical reaction in which two reactants (typically an alcohol and an acid) form an ester as the reaction product. Esters are common in organic chemistry and biological materials.Product Details of 2198-61-0

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

A comparative study of volatile flavor components in four types of zaoyu using comprehensive two-dimensional gas chromatography in combination with time-of-flight mass spectrometry was written by Chen, Zhipeng;Tang, Haiqing;Ou, Changrong;Xie, Cheng;Cao, Jinxuan;Zhang, Xin. And the article was included in Journal of Food Processing and Preservation in 2021.Electric Literature of C8H16O2 The following contents are mentioned in the article:

Volatiles of four zaoyu (Chinese traditional fermented fish) products prepared from different species of marine fish were analyzed by headspace solid-phase micro-extraction (HS-SPME) and comprehensive two-dimensional gas chromatog. in combination with time-of-flight mass spectrometry (GC 脳 GC/TOFMS). First, a 50/30螠 m DVB/CAR/PDMS was used and the influence of several parameters on the efficiency of HS-SPME such as extraction temperature, time, salting-out effect, and stirring were optimized, odor activity values (OAVs) of volatile compounds were computed based on the threshold values of aroma constituents; the characteristic volatiles and their odor characteristics of the four zaoyu were investigated. The results demonstrated that the most effective extraction of the analytes was obtained with a 40 min extraction at 50掳C with the addition of 20% NaCl and stirring at 300 r/min. Under these conditions, a total of 288 volatile components were tentatively identified based on mass spectra and comparison of linear retention indexes in the four zaoyu products. Authenticated compounds included aldehydes, esters, alcs., ketones, furans, lactones, nitrogen compounds, sulfur compounds, terpenes, phenols, etc. Among the identified types of volatile compounds, the number of esters is the largest, whereas the content of aldehydes is the highest. The results of OAVs comparisons proved that both aldehydes and esters provided the most significant contribution to the aromas of zaoyu, and each zaoyu product had its own unique active flavor components. Moreover, the OAVs of active flavor compounds common to the four examined zaoyu varied significantly. Our results substantiated that GC 脳 GC/TOFMS could provide a robust tech. means to understand the flavor characteristics of zaoyu and allow us to better evaluate and improve the flavor quality of the products with complex food matrix like zaoyu. The method present in this research is suitable to characterize the volatile constituents of aquatic products, and could also be used for component characterization of similar complex samples such as fermented fish and foods. Understanding the key aroma compounds of fermented fish and its formation mechanism could provide a guide of process optimization and flavor regulation, contributing to further studies related to volatile compounds in the field of food flavor anal. This study involved multiple reactions and reactants, such as Methyl heptanoate (cas: 106-73-0Electric Literature of C8H16O2).

Methyl heptanoate (cas: 106-73-0) belongs to esters. Esters are widespread in nature and are widely used in industry. In nature, fats are in general triesters derived from glycerol and fatty acids. Esters are responsible for the aroma of many fruits, including apples, durians, pears, bananas, pineapples, and strawberries. Esters contain a carbonyl center, which gives rise to 120掳 C鈥揅鈥揙 and O鈥揅鈥揙 angles. Unlike amides, esters are structurally flexible functional groups because rotation about the C鈥揙鈥揅 bonds has a low barrier. Their flexibility and low polarity is manifested in their physical properties; they tend to be less rigid (lower melting point) and more volatile (lower boiling point) than the corresponding amides. Electric Literature of C8H16O2

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Palladium(II) complexes bearing mixed N^N^X (X = O and S) tridentate ligands as pre-catalysts for the methoxycarbonylation of selected 1-alkenes was written by Kumar, Kamlesh;Darkwa, James. And the article was included in Polyhedron in 2017.Quality Control of Methyl heptanoate The following contents are mentioned in the article:

The methoxycarbonylation of selected 1-alkenes catalyzed by various neutral and cationic palladium(II) complexes, containing mixed N^N^X (X = O and S) tridentate ligands 2-[(3,5-dimethyl-1H-pyrazol-1-yl)methyl]-6-(phenoxymethyl)pyridine (L1), 2-[(3,5-di-tert-butyl-1H-pyrazol-1-yl)methyl]-6-(phenoxymethyl)pyridine (L2), 2-[(3,5-dimethyl-1H-pyrazol-1-yl)methyl]-6-(phenylthiomethyl)pyridine (L3), 2-[(3,5-di-tert-butyl-1H-pyrazol-1-yl)methyl]-6-(phenylthiomethyl)pyridine (L4), has been investigated. Neutral complexes, [(k²-L1)Pd(CH₃)(Cl)] (1a), [(k²-L2)Pd(CH₃)(Cl)] (2a), [(k²-L3)Pd(CH₃)(Cl)] (3a), [(k²-L4)Pd(CH₃)(Cl)] (4a), and the salts, [(k³-L3)Pd(CH₃)][BAr^F₄] (3c) and [(k³-L4)Pd(CH₃)][BAr^F₄] (4c), underwent complete decomposition during the reaction to palladium black and showed no catalytic activity. However, the addition of PPh₃ to the reaction dramatically increased the catalytic activity. On the other hand, the salts, [(k²-L1)Pd(CH₃)(PPh₃)][BAr^F₄] (1b), [(k²-L2)Pd(CH₃)(PPh₃)][BAr^F₄] (2b), [(k²-L3)Pd(CH₃)(PPh₃)][BAr^F₄] (3b) and [(k²-L4)Pd(CH₃)(PPh₃)][BAr^F₄] (4b), showed good conversion of the selected olefins to branched and linear esters without PPh₃. Addition of PPh₃ to reactions with 1b–4b significantly improved catalytic activity. All decomposition of complexes led to the formation of the known palladium complexes, [Pd(PPh₃)₂(Cl)(CH₃)] and [Pd(PPh₃)₂Cl₂]. The decomposition of all palladium complexes could be followed by NMR studies and [Pd(PPh₃)₂Cl₂] could be isolated from the crude methoxycarbonylation reaction. This study involved multiple reactions and reactants, such as Methyl heptanoate (cas: 106-73-0Quality Control of Methyl heptanoate).

Methyl heptanoate (cas: 106-73-0) belongs to esters. Volatile esters with characteristic odours are used in synthetic flavours, perfumes, and cosmetics. Certain volatile esters are used as solvents for lacquers, paints, and varnishes. Cyclic esters are called lactones, regardless of whether they are derived from an organic or inorganic acid. One example of an organic lactone is 纬-valerolactone.Quality Control of Methyl heptanoate

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Characterization of a traditional ripened cheese, Kurdish Kope: Lipolysis, lactate metabolism, the release profile of volatile compounds, and correlations with sensory characteristics was written by Esmaeilzadeh, Peiman;Ehsani, Mohammad Reza;Mizani, Maryam;Givianrad, Mohammad Hadi. And the article was included in Journal of Food Science in 2021.Product Details of 2198-61-0 The following contents are mentioned in the article:

Kope cheese has been characterized based on gross chem. composition, free fatty acids (FFAs), organic acids (OAs), volatile compounds (VCs), and sensory attributes (SAs) during 187 days of the ripening period. C16:0, C18:1cis螖9, and C14:0 were the most abundant FFAs. Lactic and acetic acids were the most prevalent OAs affecting sensory properties. principal component anal. (PCA) indicated that butanoic acid, Bu hexanoate, and 2,3-butanediol were as key VCs. Protein contents, pH (based on FFA and OA), salt in the moisture (S/M), and water activity (a_w) (based on VC and SA) were highly correlated with PC2, resulted in two distinct groups. Based on lipolysis and glycolysis studies, early-ripened cheese samples showed lipolysis and lactate metabolism more intensely compared to medium and old-ripened ones. Based on the data of VC and SA, the samples may be classified into three groups: (1) early-ripened cheeses with a salty taste, waxy to cheesy odor, and rubbery texture, (2) medium-ripened cheese with a sweet taste and cheesy odor, and (3) old-ripened cheese with a bitter taste, cheesy to pungent odor, a firm and fragile texture. Textural attributes were highly correlated with proteolysis indexes and pH. The results of sensory desirability indicated a significant correlation with pungency, bitterness, and OAs. The cheese samples ripened on the day 127 were selected as the most desirable product. Ripening time had a significant effect on the chem. composition, especially on S/M, pH, and a_w parameters, which determine the pattern as well as the intensity of biochem. pathways and the final sensory attributes. The current study intends to characterize and develop a standardized procedure for producing a traditional cheese called “Kope cheese” by determining the appropriate duration time for the ripening process, determining the main chem./biochem. compounds that are highly correlated with its unique flavor and texture and distinguishing the key processing factors (such as curd salting, pH values during brining) that have to be altered or controlled carefully during the manufacturing process. The data would help cheese manufacturers determine the optimum time of ripening in order to achieve the best flavor and texture attributes in the final product. This study involved multiple reactions and reactants, such as Isopentyl hexanoate (cas: 2198-61-0Product Details of 2198-61-0).

Isopentyl hexanoate (cas: 2198-61-0) belongs to esters. Volatile esters with characteristic odours are used in synthetic flavours, perfumes, and cosmetics. Certain volatile esters are used as solvents for lacquers, paints, and varnishes. Because of their lack of hydrogen-bond-donating ability, esters do not self-associate. Consequently, esters are more volatile than carboxylic acids of similar molecular weight.Product Details of 2198-61-0

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Electrolysis of organic acids and decomposition of peroxides. IV. Thermal decomposition of symmetrical and unsymmetrical peroxides of dicarboxylic acids was written by Goldschmidt, Stefan;Dachs, Karl. And the article was included in Chemische Berichte in 1955.HPLC of Formula: 18891-13-9 The following contents are mentioned in the article:

ClCO(CH₂)₂CO₂Me (150 g.) and 40 g. NaOH in 250 cc. H₂O added to 220 cc. 15% H₂O₂ at 0° gives (MeO₂CCH₂CH₂CO)₂O₂ (I), m. 77° (decomposition). Bz₂O₂ (10 g.) in 600 cc. absolute Et₂O treated at -2° with a solution of 1.2 g. Na in 100 cc. 96% alc. and 70 cc. ice water and the mixture washed with Et₂O gives an aqueous solution of 4.7 g. (94.4%) BzO₂Na. A solution (70 cc.) of Na₂CO₃, saturated at 15° and cooled to 0°, treated with 4 cc. ClCO(CH₂)₂CO₂Me, then with the above solution of BzO₂Na, gives benzoyl 3-carbethoxypropionyl peroxide (II), oily liquid, decompose 69-70°. Similarly were prepared the following acyl benzoyl peroxides (acyl, decomposition temperature, and % yield given): EtO₂C(CH₂)₃CO (III), 76-8°, 92; EtO₂C(CH₂)₄CO (IV), 83°, 98; EtO₂C(CH₂)₅CO (V), 91°, -. Refluxing HO₂C(CH₂)₆CO₂H, in 5 mol alc. while the solution is treated with HCl gas gives EtO₂C(CH₂)₆CO₂Et, which with an equivalent amount of HO₂C(CH₂)₆CO₂H yields EtO₂C(CH₂)₆CO₂H, and with SOCl₂ gives EtO₂C(CH₂)₆COCl (VI). A diagram is given of the thermal. decomposition apparatus Heating 50.5 g. 98.9% I in 172 g. AcOH at 100° gives 6 g. MeO₂CEt, b. 79.5°, 160 g. AcOH, b. 117°, 3.5 g. MeO₂CCH₂CH₂OAc, b₁₉ 96-8°, 9.5 g. MeO₂C(CH₂)₄CO₂Me, b₁₉ 123-4°, and 10 g. MeO₂ CCH₂CH₂CO₂CH₂CH₂CO₂Me (VII), b_1.5 149-50°. Heating CH₂:CHCN in a sealed tube with concentrated HCl gives ClCH₂CH₂CO₂H, yielding with CH₂N₂ the Me ester, which, heated with AgO₂C(CH₂)₄CO₂Me, gives VII, b₁ 149°. The decomposition of the unsym. peroxides without a solvent produces, in each case, a small amount of BzOH (BzOMe, b₃₀ 89-91°) and 4-PhC₆H₄CO₂H, m. 219°. Heating 24.2 g. II without a solvent gives, in addition to the above, 1.15 mols. CO₂, 0.3 g. EtO₂CCH:CH₂, EtO₂C(CH₂)₄CO₂Et, b₃₀ 141°, and 17 g. (85%) EtO₂CCH₂CH₂OBz, b₁ 97-100°. Similarly, 26 g. III gives 0.4 g. EtO₂CCH₂CH:CH₂, b. 118° (amide, m. 72°), 0.3 g. EtO₂C(CH₂)₆CO₂Et, b₁₁ 141°, and 17.3 g. (79%) EtO₂C(CH₂)₃OBz (VIII), b₁ 103-6°. Treating VIII with alkali, acidifying, extracting, and heating the product 8 h. at 200° gives γ-butyrolactone (IX), b₃₀ 102°; acidification of the alk. solution yields BzOH, m. 122°. Heating 29.5 g. IV as above gives 1.13 mol CO₂, 0.4 g. EtO₂CCH₂CH₂CH:CH₂, b. 142-4°, 0.3 g. EtO₂C(CH₂)₈CO₂Et, b₁₂ 166°, and 19.7 g. BzO(CH₂)₄CO₂Et (X). Hydrolysis of X gives EtOH, BzOH, and δ-valerolactone, b₁₁ 110°. Heating 31 g. V gives 1.19 mol CO₂, 0.5 g. CH₂:CH(CH₂)₄CO₂Et (XI), b₃₀ 68°, 0.5 g. EtO₂C(CH₂)₁₂CO₂Et (XII), b_0.8 50°, and 22.4 g. (83%) BzO(CH₂)₆CO₂Et (XIII). Heating XIII with 4N KOH gives HO(CH₂)₆CO₂H as a sirup. Heating 26.7 g. IV in 580 g. Me₂NPh gives BuCO₂Et, b. 144°, 7.9 g. BzOMe, b₁₂ 90°, 8.1 g. EtO₂C(CH₂)₄CO₂Me, b₁₂ 123° [HO₂C(CH₂)₄CO₂H, m. 152°], 3.2 g. δ-valerolactone, b₁₄ 113°, BzOH, m. 122°, 90 g. Me₂NPh, and 11 g. (p-Me₂NC₆H₄)₂, m. 195°. This study involved multiple reactions and reactants, such as Ethyl methyl adipate (cas: 18891-13-9HPLC of Formula: 18891-13-9).

Ethyl methyl adipate (cas: 18891-13-9) belongs to esters. Esters typically have a pleasant smell; those of low molecular weight are commonly used as fragrances and are found in essential oils and pheromones. Because of their lack of hydrogen-bond-donating ability, esters do not self-associate. Consequently, esters are more volatile than carboxylic acids of similar molecular weight.HPLC of Formula: 18891-13-9

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Reactions of Iso(thio)cyanates with Dialanes: Cycloaddition, Reductive Coupling, or Cleavage of the C=S or C=O Bond was written by Dodonov, Vladimir A.;Chen, Weixing;Liu, Li;Sokolov, Vladimir G.;Baranov, Evgeny V.;Skatova, Alexandra A.;Zhao, Yanxia;Wu, Biao;Yang, Xiao-Juan;Fedushkin, Igor L.. And the article was included in Inorganic Chemistry in 2021.Category: esters-buliding-blocks The following contents are mentioned in the article:

The dialanes [(dpp-Bian)Al-Al(dpp-Bian)] (1) and [(dpp-dad)Al(THF)-(THF)Al(dpp-dad)] (2) (dpp-Bian = 1,2-[(2,6-iPr₂C₆H₃)NC]₂C₁₂H₆, dpp-dad = [(2,6-iPr₂C₆H₃)NC(CH₃)]₂) react with some isothiocyanates, isocyanates, and diphenylketene via [2 + 4] cycloaddition of the C=O or C=S bond across the C=C-N-Al fragment to afford complexes [L(X=C-Y)Al-Al(X=C-Y)L] with an intact Al-Al single bond (L = dpp-Bian, X = PhN, Y = O (3); L = dpp-Bian, X = Ph₂C, Y = O (4); L = dpp-dad, X = BnN, Y = S (6); L = dpp-dad, X = tBuN, Y = O (7); L = dpp-dad, X = iPrN, Y = S (8); and L = dpp-dad, X = CyN, Y = S (9)). A mixed C=N and C=O mode cycloadduct, [(dpp-Bian)(TosN=C-O)Al-Al(TosN-C=O)(dpp-Bian)] (5), was obtained in the reaction of 1 with tosylisocyanate. Heating the solution of 3 resulted in a thermal transformation and a change of the cycloaddition mode from C=O to C=N to give the product [(dpp-Bian)(PhN-C=O)Al(O)Al(PhN-C=O)(dpp-Bian)] (10). The reduction of 7 and 8 with Na yielded the products [Na(THF)_n]₂[(dpp-dad^-H)(X=C-Y)Al]₂ (X = iPrN, Y = S, n = 2 (12) and X = tBuN, Y = O, n = 3 (13)) in which one of the Me groups of the backbone of the initial dpp-dad ligand was dehydrogenated. When 2 was reacted with the bulky adamantyl isocyanate AdNCO, the C-C coupling of two substrates occurred to form [(dpp-dad)Al(O=C-NAd)₂Al(dpp-dad)] (14) in which the coupled dianionic oxamide ligand bridged two Al atoms in a μ,η⁴-N,O/N,O mode. Moreover, in the presence of 2.0 equiv of Na metal, precursor 2 reacts with tBuNCS, p-TolylNCS, or Me₃SiNCO, possibly through the reduced Al^I intermediate, to yield the sulfur- or oxygen-bridged dimer [Na(solv)_n]₂[(dpp-dad)Al(μ-E)]₂ (E = S, solv = THF, n = 3 (15) and E = O, solv = DME, n = 2 (16)) upon C=S or C=O bond cleavage. Dialane 1 reacts with dimethylsulfone to give a Lewis adduct [(dpp-Bian)(Me₂SO₂)Al]₂ (17), which releases dimethylsulfone upon heating. The diamagnetic compounds 3–10 and 12–17 were characterized by NMR and IR spectroscopy. The mol. structures of 3–17 were established by single-crystal X-ray diffraction anal. Electronic structures of the compounds and possible isomers were examined by DFT calculations This study involved multiple reactions and reactants, such as Isopropylisothiocyanate (cas: 2253-73-8Category: esters-buliding-blocks).

Isopropylisothiocyanate (cas: 2253-73-8) belongs to esters. Esters are also usually derived from carboxylic acids. It may also be obtained by reaction of acid anhydride or acid halides with alcohols or by the reaction of salts of carboxylic acids with alkyl halides. Esters are more polar than ethers but less polar than alcohols. They participate in hydrogen bonds as hydrogen-bond acceptors, but cannot act as hydrogen-bond donors, unlike their parent alcohols. This ability to participate in hydrogen bonding confers some water-solubility.Category: esters-buliding-blocks

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Reactions of Iso(thio)cyanates with Dialanes: Cycloaddition, Reductive Coupling, or Cleavage of the C=S or C=O Bond was written by Dodonov, Vladimir A.;Chen, Weixing;Liu, Li;Sokolov, Vladimir G.;Baranov, Evgeny V.;Skatova, Alexandra A.;Zhao, Yanxia;Wu, Biao;Yang, Xiao-Juan;Fedushkin, Igor L.. And the article was included in Inorganic Chemistry in 2021.Application In Synthesis of Isopropylisothiocyanate The following contents are mentioned in the article:

The dialanes [(dpp-Bian)Al-Al(dpp-Bian)] (1) and [(dpp-dad)Al(THF)-(THF)Al(dpp-dad)] (2) (dpp-Bian = 1,2-[(2,6-iPr₂C₆H₃)NC]₂C₁₂H₆, dpp-dad = [(2,6-iPr₂C₆H₃)NC(CH₃)]₂) react with some isothiocyanates, isocyanates, and diphenylketene via [2 + 4] cycloaddition of the C=O or C=S bond across the C=C-N-Al fragment to afford complexes [L(X=C-Y)Al-Al(X=C-Y)L] with an intact Al-Al single bond (L = dpp-Bian, X = PhN, Y = O (3); L = dpp-Bian, X = Ph₂C, Y = O (4); L = dpp-dad, X = BnN, Y = S (6); L = dpp-dad, X = tBuN, Y = O (7); L = dpp-dad, X = iPrN, Y = S (8); and L = dpp-dad, X = CyN, Y = S (9)). A mixed C=N and C=O mode cycloadduct, [(dpp-Bian)(TosN=C-O)Al-Al(TosN-C=O)(dpp-Bian)] (5), was obtained in the reaction of 1 with tosylisocyanate. Heating the solution of 3 resulted in a thermal transformation and a change of the cycloaddition mode from C=O to C=N to give the product [(dpp-Bian)(PhN-C=O)Al(O)Al(PhN-C=O)(dpp-Bian)] (10). The reduction of 7 and 8 with Na yielded the products [Na(THF)_n]₂[(dpp-dad^-H)(X=C-Y)Al]₂ (X = iPrN, Y = S, n = 2 (12) and X = tBuN, Y = O, n = 3 (13)) in which one of the Me groups of the backbone of the initial dpp-dad ligand was dehydrogenated. When 2 was reacted with the bulky adamantyl isocyanate AdNCO, the C-C coupling of two substrates occurred to form [(dpp-dad)Al(O=C-NAd)₂Al(dpp-dad)] (14) in which the coupled dianionic oxamide ligand bridged two Al atoms in a μ,η⁴-N,O/N,O mode. Moreover, in the presence of 2.0 equiv of Na metal, precursor 2 reacts with tBuNCS, p-TolylNCS, or Me₃SiNCO, possibly through the reduced Al^I intermediate, to yield the sulfur- or oxygen-bridged dimer [Na(solv)_n]₂[(dpp-dad)Al(μ-E)]₂ (E = S, solv = THF, n = 3 (15) and E = O, solv = DME, n = 2 (16)) upon C=S or C=O bond cleavage. Dialane 1 reacts with dimethylsulfone to give a Lewis adduct [(dpp-Bian)(Me₂SO₂)Al]₂ (17), which releases dimethylsulfone upon heating. The diamagnetic compounds 3–10 and 12–17 were characterized by NMR and IR spectroscopy. The mol. structures of 3–17 were established by single-crystal X-ray diffraction anal. Electronic structures of the compounds and possible isomers were examined by DFT calculations This study involved multiple reactions and reactants, such as Isopropylisothiocyanate (cas: 2253-73-8Application In Synthesis of Isopropylisothiocyanate).

Isopropylisothiocyanate (cas: 2253-73-8) belongs to esters. Volatile esters with characteristic odours are used in synthetic flavours, perfumes, and cosmetics. Certain volatile esters are used as solvents for lacquers, paints, and varnishes. Esters are more polar than ethers but less polar than alcohols. They participate in hydrogen bonds as hydrogen-bond acceptors, but cannot act as hydrogen-bond donors, unlike their parent alcohols. This ability to participate in hydrogen bonding confers some water-solubility.Application In Synthesis of Isopropylisothiocyanate

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics

Effectiveness of high-throughput miniaturized sorbent- and solid phase microextraction techniques combined with gas chromatography-mass spectrometry analysis for a rapid screening of volatile and semi-volatile composition of wines – A comparative study was written by Mendes, Berta;Goncalves, Joao;Camara, Jose S.. And the article was included in Talanta in 2012.SDS of cas: 763-69-9 The following contents are mentioned in the article:

In this study the feasibility of different extraction procedures was evaluated in order to test their potential for the extraction of the volatile (VOCs) and semi-volatile constituents (SVOCs) from wines. In this sense, and before they could be analyzed by gas chromatog.-quadrupole first stage mass spectrometry (GC-qMS), three different high-throughput miniaturized (ad)sorptive extraction techniques, based on solid phase extraction (SPE), microextraction by packed sorbents (MEPS) and solid phase microextraction (SPME), were studied for the first time together, for the extraction step. To achieve the most complete volatile and semi-volatile signature, distinct SPE (LiChrolut EN, Poropak Q, Styrene-Divinylbenzene and Amberlite XAD-2) and MEPS (C₂, C₈, C₁₈, Silica and M1 (mixed C₈-SCX)) sorbent materials, and different SPME fiber coatings (PA, PDMS, PEG, DVB/CAR/PDMS, PDMS/DVB, and CAR/PDMS), were tested and compared. All the extraction techniques were followed by GC-qMS anal., which allowed the identification of up to 103 VOCs and SVOCs, distributed by distinct chem. families: higher alcs., esters, fatty acids, carbonyl compounds and furan compounds Mass spectra, standard compounds and retention index were used for identification purposes. SPE technique, using LiChrolut EN as sorbent (SPE_{LiChrolut EN}), was the most efficient method allowing for the identification of 78 VOCs and SVOCs, 63 and 19 more than MEPS and SPME techniques, resp. In MEPS technique the best results in terms of number of extractable/identified compounds and total peak areas of volatile and semi-volatile fraction, were obtained by using C₈ resin whereas DVB/CAR/PDMS was revealed the most efficient SPME coating to extract VOCs and SVOCs from Bual wine. Di-Et malate (18.8 ± 3.2%) was the main component found in wine SPE_{LiChrolut EN} extracts followed by Et succinate (13.5 ± 5.3%), 3-methyl-1-butanol (13.2 ± 1.7%), and 2-phenylethanol (11.2 ± 9.9%), while in SPME_DVB/CAR/PDMS technique 3-methyl-1-butanol (43.3 ± 0.6%) followed by di-Et succinate (18.9 ± 1.6%), and 2-furfural (10.4 ± 0.4%), are the major compounds The major VOCs and SVOCs isolated by MEPS_C8 were 3-methyl-1-butanol (26.8 ± 0.6%, from wine total volatile fraction), di-Et succinate (24.9 ± 0.8%), and di-Et malate (16.3 ± 0.9%). Regardless of the extraction technique, the highest extraction efficiency corresponds to esters and higher alcs. and the lowest to fatty acids. Despite some drawbacks associated with the SPE procedure such as the use of organic solvents, the time-consuming and tedious sampling procedure, it was observed that SPE_{LiChrolut EN} was the most effective technique allowing the extraction of a higher number of compounds (78) rather than the other extraction techniques studied. This study involved multiple reactions and reactants, such as Ethyl 3-ethoxypropanoate (cas: 763-69-9SDS of cas: 763-69-9).

Ethyl 3-ethoxypropanoate (cas: 763-69-9) belongs to esters. Esters typically have a pleasant smell; those of low molecular weight are commonly used as fragrances and are found in essential oils and pheromones. Cyclic esters are called lactones, regardless of whether they are derived from an organic or inorganic acid. One example of an organic lactone is γ-valerolactone.SDS of cas: 763-69-9

Referemce:
Ester – Wikipedia,
Ester – an overview | ScienceDirect Topics