We have investigated computationally the gold and palladium cocatalyzed reaction of alkynes with vinylstannane. Our work has involved a careful and thorough exploration of different mechanistic possibilities. We find that palladium acting alone as a catalyst leads to a very high reaction barrier, consistent with the experimental observation that there is no reaction in the presence of just palladium. However, the involvement of a gold(I) complex lowers the reaction barrier considerably, and the vinylstannylation reaction can proceed with a modest activation energy of about 10 kcal/mol. Our key finding is that the introduction of the gold complex avoids the formation of high-energy structures involving vinyl species in a trans arrangement on palladium. Our work confirms the role of intermediates containing both palladium and gold as suggested by Blum. For the gold–palladium cocatalyzed reaction, we also investigated an alternative mechanism suggested by Blum. With some modifications, this mechanism has a slightly higher reaction barrier, but if it does occur, then we predict a strong dependency on the counterion, in agreement with related experimental findings.

Item Type:	Refereed Article
Keywords:	bimetallic catalysis, palladium, gold, density functional theory, DFT, vinylstannylation, reaction mechanism
Research Division:	Chemical Sciences
Research Group:	Other Chemical Sciences
Research Field:	Organometallic Chemistry
Objective Division:	Expanding Knowledge
Objective Group:	Expanding Knowledge
Objective Field:	Expanding Knowledge in the Chemical Sciences
UTAS Author:	Ariafard, A (Associate Professor Alireza Ariafard)
UTAS Author:	Canty, AJ (Professor Allan Canty)
UTAS Author:	Yates, BF (Professor Brian Yates)
ID Code:	97177
Year Published:	2014
Web of Science® Times Cited:	4
Deposited By:	Chemistry
Deposited On:	2014-12-05
Last Modified:	2017-10-25
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