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Dissecting Anion Effects in Gold(I)-Catalyzed Intermolecular Cycloadditions.

ABSTRACT: From a series of gold complexes of the type [t-BuXPhosAu(MeCN)]X (X=anion), the best results in intermolecular gold(I)-catalyzed reactions are obtained with the complex with the bulky and soft anion BAr₄^F- [BAr₄^F-=3,5-bis(trifluoromethyl)phenylborate] improving the original protocols by 10-30% yield. A kinetic study on the [2+2] cycloaddition reaction of alkynes with alkenes is consistent with an scenario in which the rate-determining step is the ligand exchange to generate the (?²-phenylacetylene)gold(I) complex. We have studied in detail the subtle differences that can be attributed to the anion in this formation, which result in a substantial decrease in the formation of unproductive ?,?-(alkyne)digold(I) complexes by destabilizing the conjugated acid formed.

SUBMITTER: Homs A

PROVIDER: S-EPMC4498468 | biostudies-literature | 2014 Jan

REPOSITORIES: biostudies-literature

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Dissecting Anion Effects in Gold(I)-Catalyzed Intermolecular Cycloadditions.

Homs Anna A Obradors Carla C Lebœuf David D Echavarren Antonio M AM

Advanced synthesis & catalysis 20140101 1

From a series of gold complexes of the type [t-BuXPhosAu(MeCN)]X (X=anion), the best results in intermolecular gold(I)-catalyzed reactions are obtained with the complex with the bulky and soft anion BAr4F- [BAr4F-=3,5-bis(trifluoromethyl)phenylborate] improving the original protocols by 10-30% yield. A kinetic study on the [2+2] cycloaddition reaction of alkynes with alkenes is consistent with an scenario in which the rate-determining step is th ...[more]

PMID: 26190958

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