Generation and Application of (Diborylmethyl)zinc(II) Species: Access to Enantioenriched <i>gem</i>
-Diborylalkanes by an Asymmetric Allylic Substitution
作者:Yeosan Lee、Jinyoung Park、Seung Hwan Cho
DOI:10.1002/anie.201805476
日期:2018.9.24
We report the successful generation of (diborylmethyl)zinc(II) species by transmetallation beteween isolable (diborylmethyl)lithium and zinc(II) halide (X=Br, Cl) and their application in the synthesis of enantioenriched gem‐diborylalkanes bearing a stereogenic center at the β‐position of the diboryl groups by an asymmetric allylic substitution reaction. The reaction has a broad substrate scope, and
Copper-catalyzed asymmetric allylic substitution with aryl and ethyl Grignard reagents
作者:Khalid B. Selim、Ken-ichi Yamada、Kiyoshi Tomioka
DOI:10.1039/b809140d
日期:——
Phenyl- and ethyl-magnesium bromides undergo regioselective asymmetricallylicsubstitution with high enantioselectivity under the catalysis of chiral amidophosphane-copper(I) complexes.
Copper-Catalyzed S<sub>N</sub>2′-Selective Allylic Substitution Reaction of <i>gem</i>-Diborylalkanes
作者:Zhen-Qi Zhang、Ben Zhang、Xi Lu、Jing-Hui Liu、Xiao-Yu Lu、Bin Xiao、Yao Fu
DOI:10.1021/acs.orglett.5b03692
日期:2016.3.4
A Cu/(NHC)-catalyzed SN2′-selective substitution reaction of allylic electrophiles with gem-diborylalkanes is reported. Different substituted gem-diborylalkanes and allylic electrophiles can be employed in this reaction, and various synthetic valuable functional groups can be tolerated. The asymmetric version of this reaction was initially researched with chiral N-heterocyclic carbene (NHC) ligands
报道了Cu /(NHC)催化的烯丙基亲电试剂与宝石-二硼烷基烷烃的S N 2'-选择性取代反应。在该反应中可以使用不同的取代的宝石-二硼烷基烷烃和烯丙基亲电子试剂,并且可以容许各种合成的有价值的官能团。最初使用手性N-杂环卡宾(NHC)配体研究了该反应的不对称形式。
Iridium-Catalyzed Enantioconvergent Allylation of a Boron-Stabilized Organozinc Reagent
作者:Panchi Guo、Miao Zhan
DOI:10.1021/acs.joc.1c01076
日期:2021.7.16
An iridium-catalyzed enantioconvergent coupling of the versatile boron-stabilized organozinc reagent BpinCH2ZnI with a racemic branched allylic carbonate has been developed here, which differs from our previous work by using 1,1-bisborylmethane through the kinetic resolution process. The reaction has a broad substrate scope, and various chiral homoallylic organoboronic esters could be obtained in good
chiral boron compounds. This protocol is well suitable for activated alkenes such as vinylarenes and alkenes bearing directing groups. However, the catalytic enantioselective hydroboration of O-substituted alkenes has remained unprecedented. Here we report a Rh-catalyzedenantioselective hydroboration of silyl enol ethers (SEEs) that utilizes two new chiral phosphine ligands we developed. This approach