A Novel [2 + 2 + 1]/[2 + 1] Tandem Cycloaddition Reaction of Fischer Alkynyl Carbenes with Strained Bicyclic Olefins

Abstract

The reaction of strained bicyclic olefins with alkynyl carbenes and terminal olefins involves the creation of five new sigma C-C bonds with the concomitant formation of two new rings, thus creating a complex and densely functionalized structure in a single operation.

Group 6 Fischer carbene complexes: “chemical multitalents” for multi-component reactions

“…However, when strained bicyclic olefins such as norbornene derivatives 348 were treated with Fischer alkynyl carbene complexes 3a an unexpected behavior was found: the main products 350 incorporated two units of norbornene derivative, the carbene ligand and a carbonyl ligand with an unprecedented manner of reactivity of the alkynyl carbene complex, through the carbene carbon and both acethylenic carbons, that was also remarkable. In fact, under the reaction conditions four simple components were converted into a complex structure 350 in a single operation by the creation of five new r carboncarbon bonds that led to the concomitant formation of two new rings: cyclopentenone and cyclopropane moieties (Scheme 63) [108].…”

Multi-component reactions involving group 6 Fischer carbene complexes: a source of inspiration for future catalytic transformations

“…52 A thorough study of the scope and limitations of this reaction has recently been published. 53 Thus, a series of multicomponent adducts 143 were selectively or exclusively obtained in moderate to good yields when bicyclic olefins 142 and alkynyl FCCs 3a were mixed in refluxing toluene under a CO atmosphere (Scheme 35).…”

The chemistry of the carbon–transition metal double and triple bond: annual survey covering the year 2002

“…278) with strained bicyclic alkenes (e.g. norbornene, 277) was reported [472]. The reaction with norbornene derivatives afforded mixtures of the simple cyclopropanation product 280 and an adduct 284 incorporating CO and two moles of the norbornene.…”