Homogeneous Gold‐Catalyzed Cyclization Reactions of Alkynes with N‐ and S‐Nucleophiles

Abstract

This review covers the formation of N-a nd S-containing heterocycles,i nitiated by gold-catalyzed nucleophilic attack of N-o rS-nucleophiles ontoa lkynes. These typeso fn ucleophiles have been somewhat overlooked as compared to their C-o rO-counterparts in other reviews.I nt his particularw ork, their intramolecular gold-mediated attack ontoa lkynesi sr eviewedi nd epth.I ti ss tructured in such af ashion that the reader will get ac learv iew of which substrates react in which cyclization mode. 1I ntroduction 2N-Nucleophiles 2.Scheme1.endo-a nd exo-dig cyclization modes for heteroatom attack onto Au-activated triple bonds. REVIEWSWouter Debrouwer et al. Scheme 2. Au(I)-catalyzed formationo fp yrroles from homopropargylic azidesb yana cetylenic Schmidt reaction. Scheme3.AuCl 3 -catalyzed preparation of fluorinated pyrroles.Scheme4.Pyrrole synthesis according to Aponick and Akai. REVIEWSHomogeneous Gold-Catalyzed Cyclization Reactions of Alkynes Scheme 32. Formationo fp yrroles via 5-exo-dig cyclization with acationic Au(I) catalyst.Scheme 33. Formationo fhomoallylic pyrroles via aza-Claisen rearrangement according to Gagosz. REVIEWSHomogeneous Gold-Catalyzed Cyclization Reactions of Alkynes Scheme 58. Au-catalyzed hydroamination in the total synthesis of (À)-Quinocarcin.Scheme 59. Reactionb etween o-alkynylbenzaldehydes and anilines under AuCl catalysis.Scheme60. Intramolecular hydroamination and transfer hydrogenation. REVIEWSHomogeneous Gold-Catalyzed Cyclization Reactions of Alkynes Scheme 79. Generation of ac ontact ion pair with retention of stereochemistry,a nd the unobserved sigmatropicr earrangement with inversion of stereochemistry.Scheme 80. Au(III)-catalyzed cycloisomerization with formation of dihydrothiazoles.Scheme81. Au(I)-catalyzed generation of an Au-carbene.

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