Gold‐Catalyzed C(sp ² )H Functionalization under Au(I)/Au(III) Catalysis

Abstract

Among the newer approaches to transition metal‐catalyzed CH functionalization, Au(I)/Au(III) catalysis has emerged as a powerful synthetic tool for the construction of carbon–carbon and carbon–heteroatom bonds. The orthogonal reactivity pattern of gold catalysts as compared to other transition metal catalysts provides an excellent opportunity for the development of new modes of CH functionalization. The rapid enhancement in the field of gold‐catalyzed CH functionalization is complemented by the development of several strategies for achieving the typically arduous Au(I)/Au(III) redox cycle. This article documents all the examples of C(sp 2 )H functionalization under Au(I)/Au(III) catalysis reported so far.

Gold-catalyzed multicomponent reactions

“…Ironically, recent research revealed that gold can act as an efficient catalyst. 5 Due to the relativistic effect, 6 gold complexes have emerged as excellent soft π-Lewis acid catalysts in numerous homogeneous transformations. 7 In general, these reactions involve the activation of C–C multiple bonds towards intra- or intermolecular nucleophilic attack followed by protodeauration to provide new C–C or C–X bonds.…”

Gold-Catalyzed 1,2-Dicarbofunctionalization of Alkynes

“…23 Notably, despite such significant developments, there exist no report on 1,2-dicarbofunctionalization of alkynes using organohalides. 24 This could be attributed to various challenges like facile Au(I)- 13,25 and Ag-catalyzed 26 hydroarylation, stable vinyl-Au(I) species formation, direct cross-coupling 27 and regioselectivity issues. Notably, the successful implementation of this reaction paradigm could act as an important step towards the development various gold-catalyzed 1,2-difunctionalization reactions of alkynes using organohalides.…”

Enantioselective merged gold/organocatalysis

“…Zhou and co-workers, in 2016, developed a sequential process consisting of Au( i )-catalyzed C–H functionlizaton 27 and a chiral tertiary amine-catalyzed Michael addition reaction (Scheme 9a). 28 In the presence of 1.5 mol% Ph 3 PAuOTf, 29 diazooxindole 9a undergoes C–H insertion with the aromatic compounds 9b to form 3-aryloxindoles 9c .…”