Atroposelective Synthesis of Axially Chiral Styrenes via an Asymmetric C–H Functionalization Strategy
作者:Liang Jin、Qi-Jun Yao、Pei-Pei Xie、Ya Li、Bei-Bei Zhan、Ye-Qiang Han、Xin Hong、Bing-Feng Shi
DOI:10.1016/j.chempr.2019.12.011
日期:2020.2
Axially chiral styrenes, which exhibit a chiral axis between a substituted alkene and an aromatic ring, have been largely overlooked. The hurdle is the lower barriers to rotation compared with that of their biaryl counterparts, rendering their asymmetric synthesis more difficult. We report herein the highly atroposelective synthesis via a C−H functionalization strategy of axially chiral styrenes with an open-chained
Cu
<sup>II</sup>
‐Catalyzed Asymmetric Hydrosilylation of Diaryl‐ and Aryl Heteroaryl Ketones: Application in the Enantioselective Synthesis of Orphenadrine and Neobenodine
作者:Yao‐Zong Sui、Xi‐Chang Zhang、Jun‐Wen Wu、Shijun Li、Ji‐Ning Zhou、Min Li、Wenjun Fang、Albert S. C. Chan、Jing Wu
DOI:10.1002/chem.201200379
日期:2012.6.11
With certain amounts of sodium tert‐butoxide and tert‐butanol as additives, catalytic amounts of an inexpensive and easy‐to‐handle copper source Cu(OAc)2⋅H2O, a commercially available and air‐stable non‐racemic dipyridylphosphine ligand, as well as the stoichiometric desirable hydride donor polymethylhydrosiloxane (PMHS), formed a versatile in situ catalyst system for the enantioselective reduction
lithium–halogen exchange reaction procedure was applied to introduce electrophilic substituents to the heteroaromatics, which exhibited potential in the syntheses of pharmaceutical intermediates. In this contribution, generation and reactions of heteroaromatic lithium compounds were successfully accomplished at 10 °C in a continuous flowmicroreactor equipped with an in-line mixer. Extensive reaction results revealed