An efficient and general method for the chemoselective synthesis of unsymmetrical gem‐diborylalkanes is reported. This method is based on a late‐stage desymmetrization through nucleophilic “trifluorination”, providing chiral gem‐diborylalkanes bearing a trifluoroborate group. The reaction offers a highly modular and diastereoselective approach towards the synthesis of gem‐diborylcyclopropanes. The
A Boron Alkylidene-Alkene Cycloaddition Reaction: Application to the Synthesis of Aphanamal
作者:Xun Liu、T. Maxwell Deaton、Fredrik Haeffner、James P. Morken
DOI:10.1002/anie.201705720
日期:2017.9.11
unusual net [2+2] cycloadditionreaction between boron alkylidenes and unactivated alkenes. This reaction provides a new method for the construction of carbocyclic ring systems bearing versatile organoboronic esters. Aside from surveying the scope of this reaction, we provide details about the mechanistic underpinnings of this process, and examine its application to the synthesis of the natural product
Synthesis of 1,3‐Bis‐(boryl)alkanes through Boronic Ester Induced Consecutive Double 1,2‐Migration
作者:Cai You、Armido Studer
DOI:10.1002/anie.202007541
日期:2020.9.21
approach for the preparation of 1,3‐bis‐(boryl)alkanes is introduced. It is shown that readily generated vinylboron ate complexes react with commercially available ICH2Bpin to valuable 1,3‐bis‐(boryl)alkanes. The introduced transformation, which is experimentally easy to conduct, shows broad substrate scope and high functional‐group tolerance. Mechanistic studies reveal that the reaction does not proceed
C–O Functionalization of α-Oxyboronates: A Deoxygenative <i>gem</i>-Diborylation and <i>gem</i>-Silylborylation of Aldehydes and Ketones
作者:Lu Wang、Tao Zhang、Wei Sun、Zeyu He、Chungu Xia、Yu Lan、Chao Liu
DOI:10.1021/jacs.7b02518
日期:2017.4.12
the success of this transformation is the base-promoted C-O bond borylation or silylation of the generated α-oxyboronates. Experimental and theoretical studies exhibit that the C-O bond functionalization proceeds via an intramolecular five-membered transition-state (9-ts) boryl migration followed by a 1,2-metalate rearrangement with OBpin as a leavinggroup. The transformation occurs with an inversion
Generation of α‐Boryl Radicals and Their Conjugate Addition to Enones: Transition‐Metal‐Free Alkylation of
<i>gem</i>
‐Diborylalkanes
作者:Chaoqiang Wu、Zhicheng Bao、Bowen Dou、Jianbo Wang
DOI:10.1002/chem.202004581
日期:2021.2
A transition‐metal‐free method for the alkylation of gem‐diborylalkanes with α,β‐unsaturated ketones has been developed. It is demonstrated that the α‐boryl radicals can be generated efficiently from gem‐diborylalkanes with the aid of catechol and oxidants. The α‐boryl radicals formed through such process can be engaged in conjugate addition reaction with α,β‐unsaturated ketones. This transformation