Regio- and Enantioselective Palladium-Catalyzed Allylic Alkylation of Nitromethane with Monosubstituted Allyl Substrates: Synthesis of (<i>R</i>)-Rolipram and (<i>R</i>)-Baclofen
作者:Xiao-Fei Yang、Chang-Hua Ding、Xiao-Hui Li、Jian-Qiang Huang、Xue-Long Hou、Li-Xin Dai、Pin-Jie Wang
DOI:10.1021/jo301506p
日期:2012.10.19
The Pd-catalyzed asymmetric allylic alkylation (AAA) reaction of nitromethane with monosubstituted allyl substrates was realized for the first time to provide corresponding products in high yields with excellent regio- and enantioselectivities. The protocol was applied to the enantioselectivesynthesis of (R)-baclofen and (R)-rolipram.
Iridium-Catalyzed Allylic Alkylation Reaction with N-Aryl Phosphoramidite Ligands: Scope and Mechanistic Studies
作者:Wen-Bo Liu、Chao Zheng、Chun-Xiang Zhuo、Li-Xin Dai、Shu-Li You
DOI:10.1021/ja210923k
日期:2012.3.14
A series of N-aryl phosphoramidite ligands has been synthesized and applied to iridium-catalyzedallylicalkylation reactions, offering high regio- and enantioselectivities for a wide variety of substrates. These ligands feature the synthetic convenience and good tolerance of the ortho-substituted cinnamyl carbonates. Mechanistic studies, including DFT calculations and X-ray crystallographic analyses
一系列 N-芳基亚磷酰胺配体已被合成并应用于铱催化的烯丙基烷基化反应,为各种底物提供高区域和对映选择性。这些配体具有邻位取代的肉桂基碳酸酯的合成便利性和良好的耐受性。包括 DFT 计算和 (π-烯丙基)-Ir 配合物的 X 射线晶体学分析在内的机理研究表明,活性虹彩环是通过 C(sp(2))-H 键活化形成的。
Palladium‐Catalyzed Dearomative Methoxyallylation of 3‐Nitroindoles with Allyl Carbonates
作者:Jia‐Hao Xie、Chao Zheng、Shu‐Li You
DOI:10.1002/anie.202107139
日期:2021.10.4
with readily available allylcarbonates. Good yields (up to 86 %) and diastereoselectivity (up to >20:1 dr) are obtained for a wide range of substrates. The compatibility of gram-scale synthesis and the relatively low catalyst loading (down to 1 mol % of [Pd]) enhance the practicality of this method. The kinetic experiments indicate that the rate-determining step of this reaction is the nucleophilic attack
Difunctionalization of ketones <i>via gem</i>-bis(boronates) to synthesize quaternary carbon with high selectivity
作者:Purui Zheng、Yujie Zhai、Xiaoming Zhao、Tao XU
DOI:10.1039/c8cc07781a
日期:——
quaternary centres from ketones via the diborylation process and Suzuki–Miyaura cross-coupling reaction. This methodology, which simultaneously introduces two different kinds of electrophilic structures, exhibits a large substrate scope and high functional group tolerance. The reaction products with aldehyde and allylic groups have proved to be versatile synthons to prepare complex molecules crucial for natural
Iridium-Catalyzed Asymmetric Allylic Amination Reactions with <i>N</i>-Aryl Phosphoramidite Ligands
作者:Xiao Zhang、Wen-Bo Liu、Qiang Cheng、Shu-Li You
DOI:10.1021/acs.organomet.6b00339
日期:2016.8.8
A series of N-aryl phosphoramidite ligands were synthesized, and the iridium complexes derived from these novel ligands were proven to be efficient catalysts for asymmetric intermolecular allylic amination reactions. This C-N bond forming process readily accommodates a diverse range of amines and allylic carbonates, especially for the previously challenging ortho-substituted cinnamyl substrates. Moreover, isolation and characterization of the corresponding (pi-allyl)-iridium complex K1 reveal that the active iridacycle is generated through a C(sp(2))-H bond insertion of tetrahydroquinoline of the ligand.