Xi, Yumeng; Su, Bo; Qi, Xiaotian; Pedram, Shayun; Liu, Peng; Hartwig, John F. published the artcile< Application of Trimethylgermanyl-Substituted Bisphosphine Ligands with Enhanced Dispersion Interactions to Copper-Catalyzed Hydroboration of Disubstituted Alkenes>, Product Details of C19H34O2, the main research area is germanyl bisphosphine ligand preparation copper catalyzed hydroboration disubstituted alkene; free energy olefin hydrocupration germanyl bisphosphine ligand transition state.
The authors report the incorporation of large substituents based on heavy main group elements that are atypical in ligand architectures to enhance dispersion interactions and, thereby, enhance enantioselectivity. Specifically, the authors prepared the chiral biaryl bisphosphine ligand (TMG-SYNPHOS) containing 3,5-bis(trimethylgermanyl)phenyl groups on P and applied this ligand to the challenging problem of enantioselective hydrofunctionalization reactions of 1,1-disubstituted alkenes. Indeed, TMG-SYNPHOS forms a Cu complex that catalyzes hydroboration of 1,1-disubstituted alkenes with high levels of enantioselectivity, even when the two substituents are both primary alkyl groups. Cu catalysts bearing ligands possessing germanyl groups were much more active for hydroboration than one derived from DTBM-SEGPHOS, a ligand containing 2,5-di-tert-Bu groups and widely used for Cu-catalyzed hydrofunctionalization. This observation led to the identification of DTMGM-SEGPHOS, a bisphosphine ligand bearing 3,5-bis(trimethylgermanyl)-4-methoxyphenyl groups as the substituents on the P, as a new ligand that forms a highly active catalyst for hydroboration of unactivated 1,2-disubstituted alkenes, a class of substrates that has not readily undergone Cu-catalyzed hydroboration previously. Computational studies revealed that the enantioselectivity and catalytic efficiency of the germanyl-substituted ligands is higher than that of the silyl and tert-Bu substituted analogs because of attractive dispersion interactions between the bulky trimethyl-germanyl groups on the ancillary ligand and the alkene substrate and that Pauli repulsive interactions tended to de-crease enantioselectivity.
Journal of the American Chemical Society published new progress about Cupration (hydrocupration, mechanism). 112-63-0 belongs to class esters-buliding-blocks, and the molecular formula is C19H34O2, Product Details of C19H34O2.
Referemce:
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