Gold-Catalyzed 1,3-Transposition of Ynones

An efficient, regioselective gold-catalyzed 1,3-transposition reaction of ynones and diynones has been developed. It was found that stereoelectronic (interrupted conjugation) and electronic (extended conjugation) factors could efficiently govern the regioselectivity of this thermodynamically controlled transformation. The produced conjugated diynones were efficiently transformed into diverse alkyne-substituted five- and six-membered heterocycles

Stereocontrolled 1,3-Phosphatyloxy and 1,3-Halogen Migration Relay toward Highly Functionalized 1,3-Dienes

A double migratory cascade reaction of α-halogen-substituted propargylic phosphates to produce highly functionalized 1,3-dienes has been developed. This transformation features 1,3-phosphatyloxy group migration followed by 1,3-shifts of bromine and chlorine as well as the unprecedented 1,3-migration of iodine. The reaction is stereodivergent: (<i>Z</i>)-1,3-dienes are formed in the presence of a copper catalyst, whereas gold-catalyzed reactions exhibit inverted stereoselectivity, producing the corresponding <i>E</i> products

Au-Catalyzed Pentannulation Reaction of Propargylic Esters Occurring at C(sp³)–H Site

A gold-catalyzed cascade cyclization reaction of easily accessible propargylic esters to cyclopentenones has been developed. This transformation features an unprecedented pentannulation reaction of propargylic esters which occurs at an unactivated C­(sp³)–H site to efficiently produce functionalized mono-, bis-, and tricyclic cyclopentenones