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Solvent-Dependent Change in the Rate-Determining Step of Au(I)-Catalyzed N-Propargyl Benzamide Cyclization
Skylar G Norman1, Lin Jiao2, Jun Yi1
1Department of Chemistry, Wake Forest University, 1834 Wake Forest Road, Winston-Salem, North Carolina 27109, United States.
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The cyclization of N-propargyl benzamide with gold catalysts has become a popular benchmark reaction over the past two decades. The prevailing consensus denotes protodeauration as rate-limiting. Cyclization with [L1Au(NCCH3)]SbF6 and L1AuOTs (L1 = t-Bu2(o-biphenyl)P, also known as Johnphos) in dichloromethane and methanol in conjunction with deuterium labeling studies reveals a solvent-dependent switch to π-activation for the rate-limiting step. Computational calculations support this change of the rate-determining step.
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