Catalytic Coupling between Unactivated Aliphatic C–H Bonds and Alkynes via a Metal–Hydride Pathway
作者:Yan Xu、Michael C. Young、Guangbin Dong
DOI:10.1021/jacs.7b02020
日期:2017.4.26
We report a Rh(I)-catalyzed site-selective coupling between ketone β-C(sp3)-H bonds and aliphatic alkynes using an in situ-installed directing group. Upon hydrogenation or hydration, various β-alkylation or β-aldol products of the ketones are obtained with broad functional group tolerance. Mechanistic investigations support the involvement of a Rh-H intermediate through oxidative addition of Rh(I)
Aluminum Hydride Catalyzed Hydroboration of Alkynes
作者:Alessandro Bismuto、Stephen P. Thomas、Michael J. Cowley
DOI:10.1002/anie.201609690
日期:2016.12.5
An aluminum‐catalyzed hydroboration of alkynes using either the commercially available aluminum hydride DIBAL‐H or bench‐stable Et3Al⋅DABCO as the catalyst and H‐Bpin as both the boron reagent and stoichiometric hydride source has been developed. Mechanistic studies revealed a unique mode of reactivity in which the reaction is proposed to proceed through hydroalumination and σ‐bond metathesis between
Lithium compounds as single site catalysts for hydroboration of alkenes and alkynes
作者:Milan Kumar Bisai、Sandeep Yadav、Tamal Das、Kumar Vanka、Sakya S. Sen
DOI:10.1039/c9cc05783h
日期:——
The hydroboration of alkenes and alkynes using easily accessible lithium compounds [2,6-di-tert-butyl phenolatelithium (1a) and 1,1′ dilithioferrocene (1b)] has been achieved with good yields, high functional group tolerance and excellent chemoselectivity. Deuterium-labeling experiments confirm the cis-addition of pinacolborane. The methodology has been further extended to myrcene, which undergoes
Chemo-, regio-, and stereoselective iron-catalysed hydroboration of alkenes and alkynes
作者:Mark D. Greenhalgh、Stephen P. Thomas
DOI:10.1039/c3cc46727a
日期:——
The highly chemo-, regio-, and stereoselective synthesis of alkyl- and vinyl boronic esters with good functional group tolerance has been developed using in situ activation of a bench-stableiron(II) pre-catalyst and pinacolborane (16 examples, 45-95% yield, TOF up to 30,000 mol h(-1)). The first iron-catalysedalkene hydrogermylation is also reported.