An expedient synthesis of highly functionalized 1,3-dienes by employing cyclopropenes as C₄ units

Abstract

An efficient method has been described to synthesize 1,3-dienes by cleaving the CC bond of enaminones with cyclopropenes under very mild reaction conditions, including low rhodium catalyst-loading, ambient temperature, and a neutral solvent system.

Rh(III)-Catalyzed Enaminone-Directed C–H Coupling with Diazodicarbonyls for Skeleton-Divergent Synthesis of Isocoumarins and Naphthalenes

“…Enaminones are an important class of synthons for the assembly of a diverse range of organic structures . The ambident reactivity at electrophilic C carbonyl and C α and nucleophilic C β and N is a distinct feature that enables the achievement of such a synthetic versatility .…”

Stereoselective cyclopropanation of enamides via C–C bond cleavage of cyclopropenes

“…Cyclopropylamines with electron-withdrawing groups are prone to hydrolysis in situ to provide carbonyl compounds via proximal C-C bond cleavage. [39][40][41] However, vinylcyclopropylamides are much more stable even under harsh high temperature or acidic conditions (ESI, Table S1 †). The reaction proceeded efficiently and led to oxidative 1,3-deneyl aldehydes in the presence of AgTFA and CuCl 2 as co-metal catalysts.…”

“…1c). [39][40][41] The cyclopropylamine moiety is a key constituent of a variety of natural and non-natural compounds that exhibit important biological activities. [42][43][44][45] It is a general building block as well to prepare valuable architectures via ringopening reactions.…”

Reassembly of Unsaturated C–C Bonds by a Cutting/Insertion Cascade

“…The reaction underwent a C=C bonds cleavage of enaminones 1 progress and introducing C4 units as a new carbene sources (Scheme 3, a). 32 In addition, different substituted cyclopropenes rather than simple acetate substitution are also well compatible to provide same products under same conditions (Scheme 3, b). While acetatesubstituted cyclopropenes gave a high yield with 84%, pivalate, benzoate, and picolinate only resulted in ranging from 32% to 65% yields.…”