Selective Decarbonylation via Transition-Metal-Catalyzed Carbon–Carbon Bond Cleavage

Abstract

Transition-metal-catalyzed decarbonylation via carbon−carbon bond cleavage is an essential synthetic methodology. Given the ubiquity of carbonyl compounds, the selective decarbonylative process offers a distinct synthetic strategy using carbonyl groups as "traceless handles". This reaction has been significantly developed in recent years in many respects, including catalytic system development, mechanistic understanding, substrate scope, and application in the synthesis of complex functional molecules. Therefore, this review aims to summarize the recent progress on transition-metal-catalyzed decarbonylative process, from the discovery of new transformations to the understanding of reaction mechanisms, to reveal the great achievements and potentials in this field. The contents of this review are categorized by the type of chemical bond cleavage in the decarbonylative process. The main challenges and opportunities of the decarbonylative process are also examined with the goal of expanding the application range of decarbonylation reactions.

Divergent Coupling of Benzocyclobutenones with Indoles via C−H and C−C Activations

“…Table 3 shows that reactants with electron donating and electron withdrawing substituents at the 3-, 4-, 5-, and 6positions of indole were compatible (3 b-3 k) in this reaction. Although Ni catalysts facilitate the decarbonylation of aldehydes and esters, [13] under our conditions, aldehydes (3 c and 3 h) and esters (3 i, 3 l, 3 m and 3 n) did not compete with the decarbonylation. Various benzocyclobutenone substrates with different steric properties gave good to moderate yields (3 l-3 o).…”

Divergent Coupling of Benzocyclobutenones with Indoles via C−H and C−C Activations

“…Ni(cod) 2 dppb 67 < 5 5 [c] Ni(cod) 2 dppp 72 -6 [d] Ni ( Table 3 shows that reactants with electron donating and electron withdrawing substituents at the 3-, 4-, 5-, and 6positions of indole were compatible (3 b-3 k) in this reaction. Although Ni catalysts facilitate the decarbonylation of aldehydes and esters, [13] under our conditions, aldehydes (3 c and 3 h) and esters (3 i, 3 l, 3 m and 3 n) did not compete with the decarbonylation. Various benzocyclobutenone substrates with different steric properties gave good to moderate yields (3 l-3 o).…”

Nickel‐Catalyzed Acyl Group Transfer of o‐Alkynylphenol Esters Accompanied by C−O Bond Fission for Synthesis of Benzo[b]furan

“…Noble transitionmetal catalysts such as palladium, iridium, and ruthenium have been used for coupling esters with or without a decarbonylation path. [1,2] The high potential of low-valent nickel complexes for activation of phenyl esters under mild conditions was suggested by Yamamoto in 1980. [3] Ni complexes are not only alternatives to costly metal ones but also captivating organic chemists by their unique and diverse reactivities.…”