Low-Coordinate NHC–Zinc Hydride Complexes Catalyze Alkyne C–H Borylation and Hydroboration Using Pinacolborane
作者:Richard J. Procter、Marina Uzelac、Jessica Cid、Philip J. Rushworth、Michael J. Ingleson
DOI:10.1021/acscatal.9b01370
日期:2019.6.7
DFT calculations all support mechanisms involving organozinc species that undergo metathesis with HBPin. Furthermore, zinc-catalyzed hydroboration can proceed via a hydrozincation step, which does not require any exogenous catalyst in contrast to all previously reported alkyne hydrozincations. Bulky N-heterocyclic carbenes (NHCs) are key for effective catalysis as the NHCsteric bulk enhances the stability
Transfer C–H borylation is an isodesmic approach to the borylation reaction using B–C-containing molecules as boron sources. In this work, we report that 2-mercaptothiazole and other analogues are active for the metal-free borylation of heterocycles and terminalalkynes. Alkynes are challenging substrates to C–H borylate because they undergo side reactions with most borylating agents. The ability of
ZnBr<sub>2</sub>-Catalyzed Dehydrogenative Borylation of Terminal Alkynes
作者:Man Luo、Yi Qin、Xi Chen、Qian Xiao、Binlin Zhao、Weiwei Yao、Mengtao Ma
DOI:10.1021/acs.joc.1c01936
日期:2021.12.3
The simple, commercially available ZnBr2 has been successfully employed as a highly efficient and chemoselective catalyst for the dehydrogenativeborylation of terminalalkynes with HBpin under mild conditions. It shows a good tolerance toward various functional groups such as aryl, alkyl, heteroaryl, etc. The plausible reaction mechanism has been investigated based on the corresponding stoichiometric
The Pauson–Khand reaction using alkynylboronic esters: solving a long-standing regioselectivity issue
作者:Thierry León、Elena Fernández
DOI:10.1039/c6cc04717c
日期:——
The first intermolecularPauson-Khandreaction conducted with internal alkynylboronic esters has been described. This strategy allows the installation of the boronic ester moiety in b-position of the cyclopentenone with total...