Asymmetric Hydrogenation of Ketones and Enones with Chiral Lewis Base Derived Frustrated Lewis Pairs
作者:Bochao Gao、Xiangqing Feng、Wei Meng、Haifeng Du
DOI:10.1002/anie.201914568
日期:2020.3.9
The concept of frustratedLewispairs (FLPs) has been widely applied in various research areas, and metal-free hydrogenation undoubtedly belongs to the most significant and successful ones. In the past decade, great efforts have been devoted to the synthesis of chiral boron Lewis acids. In a sharp contrast, chiral Lewisbase derived FLPs have rarely been disclosed for the asymmetric hydrogenation.
Herein is disclosed an efficient catalyticenantioselective protonation of enol acetates by means of a readily implementable transition-metal-free chemical process. By making use of simple hygrogenocarbonates as the proton source and hydroquinine anthraquinone-1,4-diyl diether as the chiral proton shuttle, a series of cyclic enol trifluoroacetates are protonated under mild conditions to yield the corresponding
Relay Catalysis by Achiral Borane and Chiral Phosphoric Acid in the Metal-Free Asymmetric Hydrogenation of Chromones
作者:Jingjing Chen、Bochao Gao、Xiangqing Feng、Wei Meng、Haifeng Du
DOI:10.1021/acs.orglett.1c03286
日期:2021.11.5
achiral borane and chiral phosphoric acid was successfully developed for the asymmetrichydrogenation of chromones, giving the desired products in high yields with up to 95% ee. Achiral borane and chiral phosphoric acid are highly compatible in this reaction. The achiral borane acts as a Lewis acid for the first-step hydrogenation, and the chiral phosphoric acid acts as an effective chiral proton shuttle
成功开发了一种非手性硼烷和手性磷酸的中继催化策略,用于色酮的不对称氢化,以高达 95% 的 ee 的高收率得到所需产物。非手性硼烷和手性磷酸在该反应中高度相容。非手性硼烷作为第一步氢化的路易斯酸,手性磷酸作为有效的手性质子穿梭来控制对映选择性。
Fluorine-Containing Sulfonic Acid Salt, Fluorine-Containing Sulfonic Acid Salt Resin, Resist Composition, and Pattern Forming Method Using Same
申请人:Central Glass Company, Limited
公开号:US20150198879A1
公开(公告)日:2015-07-16
Disclosed is a fluorine-containing sulfonic acid salt resin having a repeating unit represented by the following general formula (3). In the formula, each A independently represents a hydrogen atom, a fluorine atom or a trifluoromethyl group, and n represents an integer of 1-10. W represents a bivalent linking group, R
01
represents a hydrogen atom or a monovalent organic group, and M
+
represents a monovalent cation. A resist composition containing this resin is further superior in sensitivity, resolution and reproducibility of mask pattern and is capable of forming a pattern with a low LER.
The potential of Song’s chiral oligoethylene glycols (oligoEGs) as catalysts was explored in the enantioselective protonation of trimethylsilyl enolethers in combination with alkali metal fluoride (KF and CsF) and in the presence of a proton source. Highly enantioselective protonations of various silylenolethers of α-substituted tetralones were achieved, producing chiral α-substituted tetralones