Diastereoselectivity in the Overman rearrangement of O-cyclohexylideneethylimidates
摘要:
Conformationally biased cyclohexylideneethanols were prepared and converted to trichloroacetimidates, which then were subjected to the thermal Overman rearrangement. The rearrangement of axially unshielded imidates was unselective, providing isomeric amides in equal ratio. The axial face shielding in the 3,3,5-trimethylcycloliexylidene system resulted in highly selective nitrogen attack from the equatorial side. (c) 2006 Elsevier Ltd. All rights reserved.
Copper(I)-catalyzed asymmetric hydrogenation of heteroaromatic ketones, cyclic and acyclic enones is reported. The choice of the chiral diphosphine ligand highly influenced enantioselectivity as well as chemoselectivity. Highly enantioselective hydrogenation of ortho-substituted heteroaromatic ketones was achieved using BDPP as the ligand. In the 1,2-selective hydrogenation of acylic enone, SEGPHOS
Modulators of Cystic Fibrosis Transmembrane Conductance Regulator
申请人:VERTEX PHARMACEUTICALS INCORPORATED
公开号:US20160095858A1
公开(公告)日:2016-04-07
The present invention features a compound of formula I:
or a pharmaceutically acceptable salt thereof, where R
1
, R
2
, R
3
, W, X, Y, Z, n, o, p, and q are defined herein, for the treatment of CFTR mediated diseases, such as cystic fibrosis. The present invention also features pharmaceutical compositions, method of treating, and kits thereof.
Catalytic asymmetric syntheses II. Hydrogenation of α,β-unsaturated ketones using chiral ruthenium complexes
作者:Viviane Massonneau、Paul Le Maux、Gérard Simonneaux
DOI:10.1016/0022-328x(87)80210-3
日期:1987.6
inthe presence of HRuCl-(TBPC)2 (TBPC = (−)-trans-1,2-bis(diphenylphosphinomethyl)cyclobutane) to give ketones with a maximum optical purity of 62%. Factors affecting the stereoselectivity of the catalytic reaction are discussed.
Identification, Characterization, and Application of Three Enoate Reductases from<i>Pseudomonas putida</i>in In Vitro Enzyme Cascade Reactions
作者:Christin Peters、Regina Kölzsch、Maria Kadow、Lilly Skalden、Florian Rudroff、Marko D. Mihovilovic、Uwe T. Bornscheuer
DOI:10.1002/cctc.201300957
日期:2014.4
Enoatereductases are versatile enzymes for the enantio‐ and regioselective addition of hydrogen to double bonds. We identified three EREDs (XenA, XenB, NemA) from Pseudomonas putida ATCC 17453 through a sequence motif search. In addition to cloning, functional expression, and biochemical characterization of these enzymes, the enoatereductases were also applied in enzymecascadereactions in combination
strains) and biodegradability (OECD 301D) of the CILs at the same time as undertaking the asymmetric catalysis study. The Pd-catalyzed enantioselective hydrogenation of the carbon–carbon double bond of α,β-unsaturatedketones under mild conditions (room temperature, 1 atm of H2) in different solvents with CILs present. The best results were obtained in i-PrOH after 18 hours of reaction with a i-PrOH/IL ratio