Photoredox‐Mediated Reaction of
<i>gem</i>
‐Diborylalkenes: Reactivity Toward Diverse 1,1‐Bisborylalkanes
作者:Nivesh Kumar、Nadim Eghbarieh、Tamar Stein、Alexander I. Shames、Ahmad Masarwa
DOI:10.1002/chem.202000603
日期:2020.4.24
The use of gem-diborylalkenes as radical-reactive groups is explored for the first time. These reactions provide an efficient and general method for the photochemicalconversion of gem-diborylalkenes to rapidly access 1,1-bisborylalkanes. This method exploits a novel photoredox decarboxylative radical addition to gem-diborylalkenes to afford α-gem-diboryl carbon-centered radicals, which benefit from
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
Copper-catalyzed dehydrogenative borylation of terminal alkynes with pinacolborane
作者:Erik A. Romero、Rodolphe Jazzar、Guy Bertrand
DOI:10.1039/c6sc02668k
日期:——
LCuOTf complexes [L = cyclic (alkyl)(amino)carbenes (CAACs) or N-heterocyclic carbenes (NHCs)] selectively promote the dehydrogenative borylation of C(sp)–H bonds at room temperature. It is shown that σ,π-bis(copper) acetylide and copper hydride complexes are the key catalytic species.
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