Direct activation of relatively unstrained carbon–carbon bonds in homogeneous systems

Abstract

New modes of chemical reactivity are of high value to synthetic organic chemistry. In this vein, carbon–carbon (C–C) activation is an emerging field that offers new possibilities for synthesizing valuable complex molecules. This review discusses the pioneering stoichiometric discoveries in this field up to the most recent synthetic applications that apply catalytic transformations. Specifically, the review focuses on C–C activation in relatively unstrained systems, including stoichiometric reactions, chelation-directed and chelation-free catalytic reactions. While the field of C–C activation of relatively unstrained systems is underdeveloped, we expect that this review will provide insight into new developments and pave the path for robust, practical applications.

Computational Study of Rh-Catalyzed Carboacylation of Olefins: Ligand-Promoted Rhodacycle Isomerization Enables Regioselective C–C Bond Functionalization of Benzocyclobutenones

“…A number of synthetically useful reactions featuring C-C bond cleavage and subsequent formation of one or more new C-C bonds have been recently developed and applied to a wide variety of substrates. 1 In particular, three- and four-membered carbocycles 2 are privileged substrates for synthesizing fused carbocycles, key motifs in various biologically important natural products. In this regard, the Dong group recently reported a series of transformations triggered by insertion of a rhodium catalyst into the relatively inert C1–C2 bond in benzocyclobutenones, 3 including carboacylation of olefins (Scheme 1), 4 decarbonylative spirocyclization, 5 and alkyne–benzocyclobutenone couplings.…”

Rh-catalyzed C–C bond cleavage by transfer hydroformylation

“…To this end, we aimed to trigger C–C bond cleavage (7–11) by chemoselective activation of aldehyde C–H bonds using Rh-catalysis (Figure 1B). Over the past fifty years, activating aldehyde C–H bonds with Rh has been thoroughly investigated (12); however, the resulting acyl–Rh III –hydrides have been trapped mainly by hydroacylation (13) and/or decarbonylation (14,15).…”

Rh-catalyzed regiodivergent hydrosilylation of acyl aminocyclopropanes controlled by monophosphine ligands

“…1 The development of methodologies for both the breaking of C–C bonds and the forming of new C–C and C–heteroatom bonds enables the synthesis of complex organic molecules in a novel and more efficient manner. In previous studies of transition-metal catalyzed C–C bond cleavage reactions, strained molecules have usually been employed.…”