Category: 5340-78-3

Estrada, Carl D. published the artcileEnantioselective Desymmetrization of 2-Aryl-1,3-propanediols by Direct O-Alkylation with a Rationally Designed Chiral Hemiboronic Acid Catalyst That Mitigates Substrate Conformational Poisoning, Quality Control of 5340-78-3, the publication is Journal of the American Chemical Society (2021), 143(11), 4162-4167, database is CAplus and MEDLINE.

Enantioselective desymmetrization by direct monofunctionalization of prochiral diols is a powerful strategy to prepare valuable synthetic intermediates in high optical purity. Boron acids can activate diols toward nucleophilic additions; however, the design of stable chiral catalysts remains a challenge and highlights the need to identify new chemotypes for this purpose. Herein, the discovery and optimization of a bench-stable chiral 9-hydroxy-9,10-boroxarophenanthrene catalyst is described and applied in the highly enantioselective desymmetrization of 2-aryl-1,3-diols using benzylic electrophiles under operationally simple, ambient conditions. Nucleophilic activation and discrimination of the enantiotopic hydroxy groups on the diol substrate occurs via a defined chair-like six-membered anionic complex with the hemiboronic heterocycle. The optimal binaphthyl-based catalyst 1g features a large aryloxytrityl group to effectively shield one of the two prochiral hydroxy groups on the diol complex, whereas a strategically placed “methyl blocker” on the boroxarophenanthrene unit mitigates the deleterious effect of a competing conformation of the complexed diol that compromised the overall efficiency of the desymmetrization process. This methodol. affords monoalkylated products in enantiomeric ratios equal or over 95:5 for a wide range of 1,3-propanediols with various 2-aryl/heteroaryl groups.

Journal of the American Chemical Society published new progress about 5340-78-3. 5340-78-3 belongs to esters-buliding-blocks, auxiliary class Aliphatic Chain, name is Ethyltert-butylacetate, and the molecular formula is C8H16O2, Quality Control of 5340-78-3.

Referemce:
https://en.wikipedia.org/wiki/Ester,
Ester – an overview | ScienceDirect Topics

Cahiez, Gerard published the artcileCopper-catalyzed conjugate addition of organomagnesium reagents to α,β-ethylenic esters: a simple high yield procedure, Category: esters-buliding-blocks, the publication is Tetrahedron Letters (1990), 31(51), 7425-8, database is CAplus.

The 1,4-conjugate addition reaction of Et α,β-unsaturated carboxylates RR¹C:CO₂Et (R = H, Me; R¹ = Me, Ph, Pr, Me₂CH) to R²MgCl (R² = Me, Bu, Me₃C, Me₂CH, Ph, MeCH:CH, CH₂:CHCH₂) in the presence of CuCl and Me₃SiCl gave branched Et carboxylates RR¹R²CCH₂CO₂Et (same R-R³). The reaction of (E)-MeCH:CHCO₂Et with BuMgCl in the presence CuCl and MeSiCl₃ was also efficient.

Tetrahedron Letters published new progress about 5340-78-3. 5340-78-3 belongs to esters-buliding-blocks, auxiliary class Aliphatic Chain, name is Ethyltert-butylacetate, and the molecular formula is C8H16O2, Category: esters-buliding-blocks.

Referemce:
https://en.wikipedia.org/wiki/Ester,
Ester – an overview | ScienceDirect Topics

Alexeev, S. G. published the artcileCorrelation of fire hazard characteristics with chemical structure. X. esters (part 2), SDS of cas: 5340-78-3, the publication is Pozharovzryvobezopasnost (2013), 22(5), 9-19, database is CAplus.

The correlation of chem. structure and fire-dangerous properties is studied among aliphatic esters of isostructure. The carbon rule well works for these compounds It is allowed to predict their physicochem. and fire-dangerous indexes. Travel of the ester group along a hydrocarbon chain practically does not lead to change of the physicochem. and fire-dangerous properties of esters. The empirical equations of calculation are offered for critical temperature (T_c (K) = -0.46(N_c)² + 27.03(N_c) + 430.1), b.p. (TB (K) = – 0.379(N_c)² + 26.448(N_c) + 254), flash point (FP (K) = -0.3107(N_c)² + 17.475(N_c) + 206.4; FP (°C) = -0.627TB (°C) – 50.4); fire (ignition) temperature (FT (K) = 13.65(N_c) + 227.6), low and upper temperature explosive limits (LTEL (K) = 13.54(N_c) + 215, UTEL = 16(N_c) + 236.2), low and upper explosive limits (LTEL (%) = 10.472(N_c)^-1.1297, UEL (%) = 1.16 + 43.051/(N_c)), combustion heat (Q (kJ/mol) = 606.2(N_c) – 321.6) and critical pressure (P_c (atm) = -10.486 + 99.243/(N_c)^0.5) from the conventional hydrocarbon chain (N_c) in an ester mol.

Pozharovzryvobezopasnost published new progress about 5340-78-3. 5340-78-3 belongs to esters-buliding-blocks, auxiliary class Aliphatic Chain, name is Ethyltert-butylacetate, and the molecular formula is C8H16O2, SDS of cas: 5340-78-3.

Referemce:
https://en.wikipedia.org/wiki/Ester,
Ester – an overview | ScienceDirect Topics