Pd-Catalyzed Decarboxylative Cycloaddition for the Synthesis of Highly Substituted δ-Lactones and Lactams

Abstract

An efficient palladium-catalyzed decarboxylative cycloaddition process of vinyl cyclic carbonates and vinyloxazolidinones for the synthesis of highly substituted δ-lactone and δ-lactam derivatives was developed. This protocol exhibits several unique characteristics, including broad substrate scope, good functional group tolerance, and operational convenience, which enables a regioselective access to a variety of lactone and lactam scaffolds in moderate to good yield. The redox-neutral catalytic system promotes formation of substituted scaffolds with in situ generation of a cyclic tetra-substituted double bond functionality.

Domino 1,4‐ and 1,4‐Addition Reactions of Ketene Silyl Thioacetals to Dialkynyl Imines Promoted by Scandium Triflate: Synthesis of Multifunctionalized δ‐Lactams

“…also reported the synthesis of δ‐lactams by Rh‐catalyzed C−H activation/annulation method using N ‐pivaloyloxy acrylamides with unactivated alkenes [11] . In 2021, Gong and Yang reported palladium‐catalyzed decarboxylative cycloaddition of vinyl cyclic carbonates for the synthesis of these compounds [12] . Several asymmetric δ‐lactam synthesis have been also reported.…”

“…[11] In 2021, Gong and Yang reported palladium-catalyzed decarboxylative cycloaddition of vinyl cyclic carbonates for the synthesis of these compounds. [12] Several asymmetric δ-lactam synthesis have been also reported. In 2013, Chi et al reported organocatalytic enantioselective γaminoalkylation of unsaturated ester for the synthesis of δlactams.…”

Recent Advances in the Synthesis and Ring‐Opening Transformations of 2‐Oxazolidinones

“…A Pd‐catalyzed decarboxylative cycloaddition of 5‐vinyl‐2‐oxazolidinones employing a CO atmosphere under balloon pressure was recently developed by Zhang and co‐workers for the construction of highly substituted δ ‐lactam derivatives 206 (Scheme 65). [106] This practical process features mild reaction conditions, broad substrate scope, and good functional‐group tolerance with both electron‐withdrawing and electron‐donating substituents on the aryl ring. Importantly, a gram‐scale decarboxylative cycloaddition reaction offered the expected lactam with a tetrasubstituted double bond with comparable yields.…”

Pd‐catalyzed decarboxylative [3 + 2] cycloaddition: Assembly of highly functionalized spirooxindoles bearing two quaternary centers

“…[17] We also have reported an efficient Pdcatalyzed domino decarboxylation/carbonylation/cyclization process of VECs for the synthesis of diverse lactones and lactams. [18] In recent years, we have designed practical and reliable methodology methods for the formation of highly functionalized skeletons. [19,20] We developed a Pd-catalyzed synthesis of spiroketal oxindoles from vinylethylene carbonates (VECs) with isatins through the in situ generation of a spiroketal system and quaternary stereocenter functionality (Scheme 1c).…”