ABSTRACT
A palladium-catalyzed thiocarbonylation reaction for the synthesis of α,ß-unsaturated thioesters from vinyl triflates with S-aryl thioformates as the thioester sources has been developed. The reaction proceeded smoothly at low temperature, and a variety of α,ß-unsaturated thioesters were produced in moderate to high yields with very good functional group tolerance. This protocol features mild reaction conditions, good substrate scope, and avoids the use of toxic CO gas or odorous thiols, which made it a worthy addition to α,ß-unsaturated thioester synthesis via a thioester transfer process.
Subject(s)
Palladium , Sulfhydryl Compounds , CatalysisABSTRACT
A novel and straightforward methodology for palladium-catalyzed carbopalladation-initiated domino carbonylative cyclization to construct bisheterocycles has been established. With TFBen as an efficient and convenient CO source, the protocol is capable of generating oxindole and 3-acylbenzofuran/3-acylindole moieties from the corresponding N-(o-iodoaryl)acrylamides and o-alkynylphenols/o-alkynylanilines with the formation of three C-C bonds and one C-O/C-N bond in a single one-step operation. A wide range of bisheterocycles bearing oxindoles and 3-acylbenzofurans/3-acylindoles were prepared in moderate to excellent yields with good functional group tolerance.
ABSTRACT
A straightforward and efficient synthesis of α,ß-unsaturated thioesters has been developed via a nickel-catalyzed thiocarbonylation reaction of vinyl triflates with arylsulfonyl chlorides. With Mo(CO)6 as both CO source and reductant, a variety of α,ß-unsaturated thioesters were obtained in moderate to good yields with very good functional group compatibility. It is noteworthy that the present method is the first example on nickel-catalyzed carbonylative synthesis of α,ß-unsaturated thioesters by using arylsulfonyl chlorides as the coupling partner.
