Scope and Mechanism of the Pt-Catalyzed Enantioselective Diboration of Monosubstituted Alkenes
作者:John R. Coombs、Fredrik Haeffner、Laura T. Kliman、James P. Morken
DOI:10.1021/ja4041016
日期:2013.7.31
The Pt-catalyzed enantioselective diboration of terminal alkenes can be accomplished in an enantioselective fashion in the presence of chiral phosphonite ligands. Optimal procedures and the substrate scope of this transformation are fully investigated. Reaction progress kinetic analysis and kinetic isotope effects suggest that the stereodefining step in the catalytic cycle is olefin migratory insertion
A site-selective and stereospecific cascade Suzuki–Miyaura annulation of alkyl 1,2-bisboronic esters and 2,2′-dihalo 1,1′-biaryls
作者:Suzanne Willems、Georgios Toupalas、Julia C. Reisenbauer、Bill Morandi
DOI:10.1039/d1cc00648g
日期:——
A cascade Suzuki–Miyaura cross-coupling giving rise to 9,10-dihydrophenanthrenes has been developed. Using biaryls with unsymmetrical substitution-pattern full site-selectivity was observed. Furthermore, this cross-coupling of an alkyl 1,2-bisboronic pinacol ester proceeds through the challenging coupling of a secondary boronate with complete stereoretention.
The use of chiral alcohols to form the Lewis acid–base *RO− → bis(pinacolato)diboron adduct, in situ, provides an opportunity to induce asymmetry in the organocatalytic diboration of alkenes and complements the well established transition metal-mediated enantioselective diboration.
Recyclable Copper Nanoparticles‐Catalyzed Hydroboration of Alkenes and β‐Borylation of α,β‐Unsaturated Carbonyl Compounds with Bis(Pinacolato)Diboron
作者:Mahadev L. Shegavi、Suresh Saini、Ramesh Bhawar、Meghana Desai Vishwantha、Shubhankar Kumar Bose
DOI:10.1002/adsc.202001616
日期:2021.4.27
Nano‐ferrite‐supported Cu nanoparticles (Fe‐dopamine‐Cu NPs) catalyzed anti‐Markovnikov‐selective hydroboration of alkenes with B2pin2 is reported undermild reaction conditions. This protocol can be applied to a broad range of substrates with high functional group compatibility. In addition, we demonstrated the use of Fe‐dopamine‐Cu NPs as a catalyst for the β‐borylation of α,β‐unsaturatedketones and ester, providing
Vicinal Diboration of Alkyl Bromides via Tandem Catalysis
作者:Xiao-Xu Wang、Lei Li、Tian-Jun Gong、Bin Xiao、Xi Lu、Yao Fu
DOI:10.1021/acs.orglett.9b01481
日期:2019.6.7
Vicinal diboration of alkylbromides via tandem catalysis is reported. The reported reaction exhibits a broad substrate scope, good functional group compatibility, and regioselectivity. Moreover, it shows good practicality due to the easy accessibility of alkylbromides in combination with diverse transformations of diboronates. Mechanism study indicates that terminal alkenes are generated selectively