RESUMO
We report the first catalyst-controlled regiodivergent method that enables the synthesis of structurally diverse 1,2,3,4-tetrasubstituted conjugated dienes with excellent regio- and stereochemical outcomes from the same set of readily available propargyl esters and diaryliodonium salts. In this diene chemistry, the in situ generated, highly electrophilic aryl-CuIII complex serves not only as a π-Lewis acid catalyst for alkyne activation/acyloxy migration but also as an aryl electrophile equivalent. The competitive arylative 1,2- and 1,3-acyloxy migration patterns are exquisitely dictated by Cu and Au/Cu relay catalyses, respectively, providing a modular and attractive approach to traditionally inaccessible tetrasubstituted 1,3-dienes in a regiodivergent manner. Finally, the synthetic utility of this method is demonstrated by further synthetic derivatization of 1,3-dienes into an array of useful compounds.
RESUMO
Catalyst-controlled regiodivergent catalysis is a vital chemical tool that allows efficient access to large collections of structurally diverse molecules from a common precursor but remains a challenge. We report a catalyst-controlled, tunable, and predictable regiodivergency in transforming the internal aliphatic propargyl esters into diverse libraries of highly substituted 1,3-dienyl and allyl products by Pd-catalysis. Depending on the ligand employed, the palladium catalyst can involve two typical approaches: electrophilic palladium catalysis and a sequential oxidative addition-reductive elimination pathway. This regiodivergent protocol endows facile access to four regioisomers with high regio- and stereoselectivity from the common propargyl esters. In terms of synthetic utility, a notable feature of this protocol is amenable to structural diversification of bioactive relevant molecules, enabling rapid assembly of many useful structural analogs of pharmaceutical candidates.