Homogeneous Gold-Catalyzed Oxidative Carboheterofunctionalization of Alkenes

Abstract

Homogeneous carboamination, carboalkoxylation and carbolactonization of terminal alkenes are realized via oxidative gold catalysis, providing expedient access to various substituted N- or O-heterocycles. Deuterium-labeling studies established the anti nature of the alkene functionalization and the indispensible role of Au(I)/Au(III) catalysis. This study constitutes the first example of catalytically converting C(sp(3))-Au bonds into C(sp(3))--C(sp(2)) bonds in a cross-coupling manner and opens new opportunities to study gold alkene catalysis where alkylgold intermediates can be readily functionalized intermolecularly.

AuI/AuIII Catalysis: An Alternative Approach for CC Oxidative Coupling

“…These reactions proceed via alkylgold intermediates in which the metal atom is bonded to an sp Cyclizing terminal alkenes 50 bearing g-alcohol substituents in the presence of PPh 3 AuCl (5 mol %), arylboronic acids (2 equiv), and Selectfluor (2 equiv) led cleanly to benzyl tetrahydrofurans 51 in up to 73 % yield. [43] Notably, homodimerized or protode-A C H T U N G T R E N N U N G aurated products were observed in only trace amounts, whilst no alkene products resulting from b-hydride elimination were isolated (Scheme 20). Changing the nature and position of the intramolecular nucleophile gave access to a wide-variety of benzyl-substituted heterocycles including tetrahydropyrans 52, pyrrolidines 53, piperidines 54, and lactones 55 in moderate to high yields.…”

Passive F+‐Oxidationsmittel ermöglichen die selektive reduktive Eliminierung hochvalenter Metallzentren in der Katalyse

“…(72) [23][24][25]. [61][62][63] Unabhängig voneinander beschrieben Zhang [61] und Toste [62] Difunktionalisierungen von Olefinen, bei denen ein Au I -Katalysator zuerst durch Selectfluor (66) [62] bimolekularen Mechanismus der reduktiven Eliminierung vorgeschlagen, der über einen fünfgliedrigen cyclischen Übergangszustand 89 (Schema 24) verläuft. [62,63] [67] oder eine dimere oktaedrische Geometrie [15a] annimmt.…”

Unique distal size selectivity with a digold catalyst during alkyne homocoupling

“…The reductive elimination from Au(III) complexes to form new C sp 3-X and C sp 2-X bonds (X ¼ heteroatom, C sp 3, C sp 2,y) is a well-known process 13,[29][30][31][32] that has been recently reported to occur very rapidly (even at À 52°C) 33 , faster than in palladium (II). Au(III) intermediates have been isolated and characterized [34][35][36] .…”