Geometric
<i>E</i>
→
<i>Z</i>
Isomerisation of Alkenyl Silanes by Selective Energy Transfer Catalysis: Stereodivergent Synthesis of Triarylethylenes via a Formal
<i>anti</i>
‐Metallometallation
作者:Svenja I. Faßbender、John J. Molloy、Christian Mück‐Lichtenfeld、Ryan Gilmour
DOI:10.1002/anie.201910169
日期:2019.12.16
An efficient geometrical E→Z isomerisation of alkenyl silanes is disclosed via selective energy transfer using an inexpensive organic sensitiser. Characterised by operational simplicity, short reaction times (2 h), and broad substrate tolerance, the reaction displays high selectivity for trisubstituted systems (Z/E up to 95:5). In contrast to thermal activation, directionality results from deconjugation
A highly selective hydrogenation of alkynesusing an air-stable and readily available manganese catalyst has been achieved. The reaction proceeds under mild reaction conditions and tolerates various functional groups, resulting in (Z)-alkenes and allylic alcohols in high yields. Mechanistic experiments suggest that the reaction proceeds via a bifunctional activation involving metal–ligand cooperativity