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Title: Kinetics and Mechanism of the Gold‐Catalyzed Hydroamination of 1,1‐Dimethylallene with N ‐Methylaniline
Abstract

The mechanism of the intermolecular hydroamination of 3‐methylbuta‐1,2‐diene (1) withN‐methylaniline (2) catalyzed by (IPr)AuOTf has been studied by employing a combination of kinetic analysis, deuterium labelling studies, and in situ spectral analysis of catalytically active mixtures. The results of these and additional experiments are consistent with a mechanism for hydroamination involving reversible, endergonic displacement ofN‐methylaniline from [(IPr)Au(NHMePh)]+(4) by allene to form the cationic gold π‐C1,C2‐allene complex [(IPr)Au(η2‐H2C=C=CMe2)]+(I), which is in rapid, endergonic equilibrium with the regioisomeric π‐C2,C3‐allene complex [(IPr)Au(η2‐Me2C=C=CH2)]+(I′). Rapid and reversible outer‐sphere addition of2to the terminal allene carbon atom ofI′to form gold vinyl complex (IPr)Au[C(=CH2)CMe2NMePh] (II) is superimposed on the slower addition of2to the terminal allene carbon atom ofIto form gold vinyl complex (IPr)Au[C(=CMe2)CH2NMePh] (III). Selective protodeauration ofIIIreleasesN‐methyl‐N‐(3‐methylbut‐2‐en‐1‐yl)aniline (3 a) with regeneration of4. At high conversion, gold vinyl complexIIis competitively trapped by an (IPr)Au+fragment to form the cationic bis(gold) vinyl complex {[(IPr)Au]2[C(=CH2)CMe2NMePh]}+(6).

 
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NSF-PAR ID:
10237370
Author(s) / Creator(s):
 ;  ;  ;  ;  ;  
Publisher / Repository:
Wiley Blackwell (John Wiley & Sons)
Date Published:
Journal Name:
Chemistry – A European Journal
Volume:
27
Issue:
40
ISSN:
0947-6539
Page Range / eLocation ID:
p. 10377-10386
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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