Conjugated aldehydes and ketones undergo reaction with Me2PhSiBpin (pin: pinacolato) catalyzed by Au nanoparticles supported on TiO2 forming exclusively the β-borylation products, via the intermediate formation of the labile silaboration adducts. This chemoselectivity pathway is complementary to the so far known analogous reaction catalyzed by other metals, where β-silylation occurs instead. β-Borylation
One-Pot Three-Component Highly Selective Synthesis of Homoallylboronates by Using Metal-Free Catalysis
作者:Ismail Ibrahem、Palle Breistein、Armando Córdova
DOI:10.1002/chem.201103572
日期:2012.4.23
Metal‐free selectivity: The first metal‐free one‐pot three‐component highly chemo‐ and regioselective catalytic synthesis of homoallylboranes using simple N‐heterocyclic carbenes (NHC) and amines is presented. The catalytic reaction between B2(pin)2, α,β‐unsaturated aldehydes and 2‐(triphenylphosphoranylidene)acetate esters proceeds through a catalytic metal‐free β‐boration/Wittig cascade sequence