Candida antarctica lipase A and Pseudomonas stutzeri lipase as a pair of stereocomplementary enzymes for the resolution of 1,2-diarylethanols and 1,2-diarylethanamines
摘要:
Candida antarctica lipase A (CALA) and Pseudomonas stutzeri lipase (PSL) displayed opposite enantioselectivities in the acylation of 1,2-diphenylethanol and 1,2-diphenylethanamine. CALA was (S)-selective while PSL was (R)-selective. In addition, fourteen different 1,2-diarylethanols were tested as the substrates of CALA. It was found that most of them were accepted by CALA with high enantioselectivity. The DKR of five representative substrates by the combination of CALA and a ruthenium-based racemization catalyst provided good yields (82-91%) and acceptable enantiopurities (87-94% ee). (C) 2012 Elsevier Ltd. All rights reserved.
Pd-Catalyzed Conjunctive Cross-Coupling between Grignard-Derived Boron “Ate” Complexes and C(sp<sup>2</sup>) Halides or Triflates: NaOTf as a Grignard Activator and Halide Scavenger
作者:Gabriel J. Lovinger、Mark D. Aparece、James P. Morken
DOI:10.1021/jacs.6b12663
日期:2017.3.1
Catalytic enantioselectiveconjunctivecross-couplings that employ Grignard reagents are shown to furnish an array of nonracemic chiral organoboronic esters in an efficient and highly selective fashion. The utility of sodium triflate in facilitating this reaction is two-fold: it enables "ate" complex formation and overcomes catalytic inhibition by halide ions.