Sonogashira-Like Coupling Reactions with Phosphine–Gold(I) Alkynyl Complexes

Abstract

Phosphine-gold(I) alkynyl complexes are stable compounds that can be subjected to palladium-catalyzed cross-coupling reactions. This article outlines the synthesis of such compounds and their ability to play the role as substrates in Sonogashira couplings is covered. This synthetic approach is particularly attractive when the related terminal alkynes are unstable. 1 Introduction 2 Phosphine-Gold(I) Alkynyl Complexes 3 Sonogashira-Like Couplings 4 Transmetalation Step-Mechanistic Insight 5 Acetylenic Scaffolding with Tetraethynylethene Derivatives 6 Conclusion

Catalytic Arylative Endo Cyclization of Gold Acetylides: Access to 3,4‐Diphenyl Isoquinoline, 2,3‐Diphenyl Indole, and Mesoionic Normal NHC–Gold Complex

“…In this case, gold in the acetylide acts as a directing group to realize the regioselective nucleophilic attack at the α‐carbon in gold acetylide moiety. In addition, gold acetylides are generally quite stable and have been used as alternative substrates in C−C coupling reactions in the case that the corresponding terminal alkynes are unstable [9] . To date, studies on the reactivity of the vicinal diaurated alkene species E remain very rare.…”

“…[7] Later,w ef ound that in the presence of base and two equivalents of Au salt, F couldu ndergo 6-endo-dig cyclization to give six-membered vicinal diaurated alkene species of type E,i ndicatingt he involvement of the formation of a s,pdigold acetylide species D. [8] In this case, gold in the acetylide acts as ad irecting group to realize the regioselectiven ucleophilic attack at the a-carbon in gold acetylide moiety.I na ddition, gold acetylides are generally quite stable and have been used as alternative substrates in CÀCc oupling reactionsi nt he case that the corresponding terminal alkynesa re unstable. [9] To date, studies on ther eactivity of the vicinal diaurated alkene species E remainv ery rare. We previously reported E derived from F could undergo homocouplingt oa fford gold vinyl complexes.…”

“…4. X-ray crystal structure of 10.Hydrogen atoms have been omitted for clarity.Selectedbondlengths (): Au1ÀC1 1.994(6), Au2ÀC2 2.057(6), O1ÀC5 1.221(7), N2ÀC1 1.341(7),N 2 ÀC2 1.399(7), C2ÀC6 1.373(8), C5ÀC6 1.454 (9). CCDC 1936628 (2), 1936625 (3), 1514555 (9), 1514556 (10) and 2005824 (11)c ontain the supplementary crystallographic data for this paper.T hese data are provided free of charge by TheCambridge Crystallographic Data Centre.…”