40628-81-7Relevant articles and documents
Rh-catalyzed asymmetric hydrogenation of α-aryl-β-alkylvinyl esters with chiral ferrocenylphosphine-phosphoramidite ligand
Dong, Chao,Liu, Dao-Sheng,Zhang, Lei,Hu, Xiang-Ping
supporting information, (2021/02/03)
An enantioselective Rh-catalyzed hydrogenation of E/Z mixtures of trisubstituted vinyl esters has been disclosed. With a combination of [Rh(COD)2]BF4 and a structurally fine-tuning chiral ferrocenylphosphine-phosphoramidite ligand as the catalyst, a variety of E/Z mixtures of α-aryl-β-alkylvinyl esters have been successfully hydrogenated in high yields and with good to high enantioselectivities (up to 96% ee). The presence of a small amount of tBuOH proved to be beneficial to improve the hydrogenation outcome.
Highly Focused Library-Based Engineering of Candida antarctica Lipase B with (S)-Selectivity Towards sec-Alcohols
Cen, Yixin,Li, Danyang,Xu, Jian,Wu, Qiongsi,Wu, Qi,Lin, Xianfu
, p. 126 - 134 (2018/12/05)
Candida antarctica lipase B (CALB) is one of the most extensively used biocatalysts in both academia and industry and exhibits remarkable (R)-enantioselectivity for various chiral sec-alcohols. Considering the significance of tailor-made stereoselectivity in organic synthesis, a discovery of enantiocomplementary lipase mutants with high (R)- and (S)-selectivity is valuable and highly desired. Herein, we report a highly efficient directed evolution strategy, using only 4 representative amino acids, namely, alanine (A), leucine (L), lysine (K), tryptophan (W) at each mutated site to create an extremely small library of CALB variants requiring notably less screening. The obtained best mutant with three mutations W104V/A281L/A282K displayed highly reversed (S)-selectivity towards a series of sec-alcohol with E values up to 115 (conv. 50%, ee 94%). Compared with the previously reported (S)-selective CALB variant, W104A, a single mutation provided less selectivity, while the synergistic effects of three mutations in the best variant endow better (S)-selectivity and a broader substrate scope than the W104A variant. Structural analysis and molecular dynamics simulation unveiled the source of reversed enantioselectivity. (Figure presented.).
A novel lipase enzyme panel exhibiting superior activity and selectivity over lipase B from Candida antarctica for the kinetic resolution of secondary alcohols
O'Neill, Maeve,Beecher, Denis,Mangan, David,Rowan, Andrew S.,Monte, Agnieszka,Sroka, Stefan,Modregger, Jan,Hundle, Bhupinder,Moody, Thomas S.
experimental part, p. 583 - 586 (2012/08/13)
A novel, commercially available lipase enzyme panel performing kinetic bioresolutions of a number of secondary alcohols is reported. The secondary alcohols that have been chosen are known from the literature to be particularly challenging substrates to resolve. Following initial screening, four co-solvents were investigated for each lead enzyme in an effort to assess their tolerance to common organic solvents. The superiority of these novel enzymes over lipase B from Candida antarctica (CALB) has been demonstrated.
