A copper-catalyzed highly regio- and stereoselective silaboration of alkynes was developed. In this work, direct cis-difunctionalization of alkynes was realized with silaboronate reagent and copper catalyst in aprotic solvents. The regiodivergent silaborations were controlled by tuning the copper catalysts and phosphine ligands used in reactions. This protocol provides an efficient and practical method
esters to terminalalkynes can be switched by the choice of phosphorus ligands on the palladium catalysts. The silaboration proceeds with normal regioselectivity in the presence of (eta(3)-C(3)H(5))Pd(PPh(3))Cl (1.0 mol %) to give 1-boryl-2-silyl-1-alkenes in high yields. In sharp contrast, selective formation of the inverse regioisomers, 2-boryl-1-silyl-1-alkenes, takes place when the reaction is carried
Regio- and stereo-selective silaboration of alkynes catalysed by palladium and platinum complexes
作者:Michinori Suginome、Hiroshi Nakamura、Yoshihiko Ito
DOI:10.1039/cc9960002777
日期:——
Addition of the silicon–boron bond across carbon–carbon triple bonds, i.e. silaboration is most effectively catalysed by a palladium(0)–tert-alkyl isocyanide complex to give (Z)-1-boryl-2-silyl alkenes with high regio- and stereo-selectivity, which are useful for synthesis of stereodefined alkenylsilanes.
(N-Heterocyclic Carbene)<sub>2</sub>-Pd(0)-Catalyzed Silaboration of Internal and Terminal Alkynes: Scope and Mechanistic Studies
作者:Melvyn B. Ansell、John Spencer、Oscar Navarro
DOI:10.1021/acscatal.6b00127
日期:2016.4.1
Pd(ITMe)2(PhC≡CPh) acts as a highly reactive precatalyst in the silaboration of terminal and internal alkynes to yield a number of known and novel 1-silyl-2-boryl alkenes. Unprecedented mild reaction temperatures for terminalalkynes, short reaction times, and low catalytic loadings are reported. During mechanisticstudies, cis-Pd(ITMe)2(SiMe2Ph)(Bpin) was directly synthesized by oxidative addition of
A new protocol has been designed for the in situgeneration of unstable Si−Zn species through the reaction of dialkylzinc, phosphine, and silylborane (Si−B). Successive reactions with various terminalalkynes using this protocol enabled highly controllable regio‐/stereo‐/chemoselective silylzincation and silaboration on demand without the need for a transition‐metal catalyst.