om201223j_si_001.pdf (1.28 MB)
Synthesis of Calcium and Ytterbium Complexes Supported by a Tridentate Imino-Amidinate Ligand and Their Application in the Intermolecular Hydrophosphination of Alkenes and Alkynes
journal contribution
posted on 2016-02-22, 06:27 authored by Hongfan Hu, Chunming CuiWell-defined calcium and ytterbium complexes [{2-NC(Ph)NArC6H4CHNAr}M{N(SiMe3)2}(THF)]
(M = Ca, Yb; Ar = 2,6-iPr2C6H3) have been synthesized and characterized. They catalyze
the intermolecular hydrophosphination of alkenes, dienes, and alkynes
with high activity and selectivity under mild conditions. Highly selective
1,4-additions (94–100%) for the conjugated dienes examined
have been observed with both catalysts. The calcium complex exclusively
catalyzes anti addition to alkynes, including terminal alkynes, while
the ytterbium, in most cases, catalyzes syn addition. The calcium
catalyst could promote hydrophosphination of hindered alkenes such
as stilbene under relatively mild conditions.