Control of enantioselectivity in the enzymatic reduction of halogenated acetophenone analogs by substituent positions and sizes
作者:Afifa Ayu Koesoema、Daron M. Standley、Shusuke Ohshima、Mayumi Tamura、Tomoko Matsuda
DOI:10.1016/j.tetlet.2020.151820
日期:2020.4
We utilized acetophenone reductase from Geotrichum candidum NBRC 4597 (GcAPRD), wild type and Trp288Ala mutant, to reduce halogenated acetophenone analogs to their corresponding (S)- and (R)-alcohols beneficial as pharmaceutical intermediates. Reduction by wild type resulted in excellent (S)-enantioselectivity for all of the substrates tested. Meanwhile, reduction by Trp288Ala resulted in high (R)-enantioselectivity
Herein, we report the first efficient catalytic system for the asymmetric alkylation of aldehydes with organolithium reagents in the presence of titanium(IV) isopropoxide. A variety of alkyllithium reagents can be added to aromaticaldehydes in good yields with high enantioselectivities in a simple one-pot procedure under mild conditions.
The enantioselectiveaddition of organozincreagents to aromatic and aliphatic aldehydes 1 gives secondary alcohols 2 with excellent enantioselectivities in high yields through the catalytic use of (R)-3,3′-bis(diphenylphosphinoyl)-BINOL (3) or (R)-3,3′-bis(diphenylthiophosphinoyl)-BINOL (4) without Ti(IV) complexes. The coordination of the O or S atom of a (thio)phosphinoyl group bearing a BINOL backbone
A highlyenantioselective dialkylzinc (R22Zn) addition to a series of aromatic, aliphatic, and heteroaromatic aldehydes (5) was developed based on conjugate Lewis acid−Lewis base catalysis. Bifunctional BINOL ligands bearing phosphine oxides [P(O)R2] (7), phosphonates [P(O)(OR)2] (8 and 9), or phosphoramides [P(O)(NR2)2] (10) at the 3,3‘-positions were prepared by using a phospho-Fries rearrangement
Catalytic Enantioselective Addition of MeMgBr and Other Grignard Reagents to Aldehydes
作者:Emilio Fernández-Mateos、Beatriz Maciá、Diego J. Ramón、Miguel Yus
DOI:10.1002/ejoc.201101283
日期:2011.12
Herein, we report an efficient catalyst for the challenging enantioselectiveaddition of MeMgBr to aldehydes. Unprecedented yields and enantioselectivities are achieved in the reaction with a broad range of aldehydes. Moreover, a variety of Grignard reagents can be also added to aromatic and aliphatic aldehydes in good yields and enantioselectivities in a simple one-pot procedure under mild conditions.