Using triethynylphosphine ligands bearing bulky end caps to create a holey catalytic environment: Application to gold(I)-catalyzed alkyne cyclizations
Using triethynylphosphine ligands bearing bulky end caps to create a holey catalytic environment: Application to gold(I)-catalyzed alkyne cyclizations
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DOI：
10.1021/ja066800c
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发表时间：
2006-12-27
影响因子：
15
通讯作者：
Sawamura, Masaya
中科院分区：
文献类型：
--
作者：
Ochida, Atsuko;Ito, Hideto;Sawamura, Masaya
报道了在炔末端带有大体积封端的膦基炔，即三[(三芳基甲硅烷基)乙炔基]膦的合成、性质和催化用途。新型膦最显着的特征是多孔分子形状，具有深而大的金属结合腔。多孔膦在金(I)催化的炔酮酯和1,7-烯炔的六元环和七元环形成环化中表现出显着的速率增强。据认为，配体中的空腔迫使炔属化合物的亲核中心（烯醇或烯烃）靠近与金结合的炔烃，从而使闭环抗攻击成为可能。
The synthesis, properties and catalytic uses of phosphinoalkynes bearing bulky end caps at the alkyne termini, that is, tris[(triarylsilyl)ethynyl]phosphines are reported. The most salient feature of the new phosphines is the holey molecular shape possessing a deep and large-scale metal-binding cavity. The holey phosphines displayed remarkable rate enhancement in the gold(I)-catalyzed six- and seven-membered ring forming cyclizations of acetylenic keto esters and 1,7-enynes. It is proposed that the cavity in the ligand forces a nucleophilic center (enol or alkene) of the acetylenic compounds close to the gold-bound alkyne, making ring-closing anti attack feasible.