Copper(II)‐catalyzed Domino Reaction of the Acyclic Ketene‐(S,S)‐Acetals with Diazo Compounds: Convenient Synthesis of Poly‐substituted Thiophenes

Abstract

Copper(II)-catalyzed domino reaction between the acyclic ketene-(S,S)-acetals and diazo compounds has been successfully developed. This reaction proceeds through a sequential formation of electrophilic copper carbenoid, sulfur ylide and subsequent CÀ S bond coupling and cleavage. Notably, the domino reaction features broad the readily available acyclic ketene-(S,S)-acetals scope and provides a new strategy for the synthesis of poly-substituted thiophenes.

Selectfluor-Promoted Intramolecular N–S Bond Formation of α-Carbamoyl Ketene Dithioacetals in the Presence of Water: Synthesis of Multifunctionalized Isothiazolones

“…After that, A undergoes intramolecular cyclization to give cyclic sulfonium salt B (path a), which might also be generated through dehydration of intermediate C1 from a nucleophilic substitution process of A with molecular H 2 O (path b). Subsequently, intermediate B undergoes C–S bond cleavage in the presence of H 2 O to afford intermediate D followed by further oxidation, leading to 5-sulfinyl product 2a . Correspondingly, the released acid during the reaction was captured by the amine produced from the consumed Selectfluor, and E was isolated successfully.…”

Copper-Catalyzed Annulative Coupling of S,S-Disubstituted Enones with Diazo Compounds to Access Highly Functionalized Thiophene Derivatives

“…Transition-metal-catalyzed reactions using diazo compounds as the carbene precursors allow for the rapid assembly of useful complex molecules which cannot be readily accessed by other methods . As versatile C1 synthons, diazo compounds are potentially used for the direct construction of cyclic architectures through cycloaddition or annulative coupling reactions. , Diazo compounds are amphiphilic, and the negatively polarized diazo carbon atom is nucleophilic, while the metal carbene species generated from a diazo compound has an electron-deficient carbene center . Thus, diazo compounds can exhibit diverse reactivities.…”

Silver-Catalyzed Cascade Cyclization Reaction of Isocyanides with Sulfoxonium Ylides: Synthesis of 3-Aminofurans and 4-Aminoquinolines

“…However, to the best of our knowledge, the transition-metal-catalyzed carbene-transfer reaction of sulfoxonium ylides with isocyanides has not been reported. As part of our continuing interest in the applications of diazo compounds and isocyanides, herein we report a novel silver-catalyzed coupling cyclization of isocyanides with sulfoxonium ylides for the first time. This reaction offers a new and efficient strategy for the synthesis of highly functionalized 3-aminofurans and 4-aminoquinolines in a single step from readily available starting materials.…”