Copper-Catalyzed Stereodefined Construction of Acrylic Acid Derivatives from Terminal Alkynes via CO₂ Insertion

Abstract

IPrCuCl catalyzes the CO insertion reaction undergone by a dialkylvinylborane intermediate derived from alkynyltrialkylborate by a 1,2-alkyl group migration to afford α-alkyl acrylic acids with excellent regio- and stereoselectivities.

Construction of C–Cu Bond: A Useful Strategy in CO2 Conversion

“…Recently, Kimura’s group reported the novel copper-catalyzed synthesis of acrylic acid derivatives from terminal alkynes, triethyl boron, and CO 2 . It is speculated that vinyldiethylborane IM14 can be generated in situ , and then a transmetalation occurs between the vinyldiethylborane intermediate and a carbene-copper, generating nucleophilic vinylcopper intermediate IM15 which can be used in CO 2 insertion (Scheme ).…”

“…Recently, Kimura's group reported the novel copper-catalyzed synthesis of acrylic acid derivatives from terminal alkynes, triethyl boron, and CO 2 . 37 It is speculated that vinyldiethylborane IM14 can be generated in situ, and then a transmetalation occurs between the vinyldiethylborane intermediate and a carbene-copper, generating nucleophilic vinylcopper intermediate IM15 which can be used in CO 2 insertion (Scheme 13). In addition to triethyl boron, this protocol can be applied to other commercially available trialkylboranes such as tri-n-butylborane and the organoboranes prepared from hydroboration of alkenes.…”

Challenges and recent advancements in the transformation of CO2into carboxylic acids: straightforward assembly with homogeneous 3d metals

“…162,163,230,231 From this point of view, Kimura et al were interested in the synthesis of α-substituted acrylic acids by employing a multicomponent coupling reaction of terminal alkynes, trialkylboranes and CO 2 . 232 After a broad range of optimization studies, they were able to synthesize (2 E )-2-(phenylmethylene)butanoic acid ( 214 ) in 78% yield from phenylacetylene ( 213 ), MeOK, Et 3 B, and IPrCuCl in dioxane as the solvent under a CO 2 atmosphere. The procedure was independent of the substituent on the aromatic terminal alkyne, as moderate to good yields (56–83%) were observed.…”

Origins of regio- and stereoselectivity in Cu-catalyzed alkyne difunctionalization with CO2 and organoboranes

“…In this regard, the Kimura group recently developed a copper-catalyzed three-component coupling reaction with terminal alkynes, CO 2 and trialkyl boranes (Scheme 1b). 3 The reaction shows excellent controls of regio- and stereoselectivities, only favoring the 1,1- E -selective product ( 1 ) among a series of possible configurations of acrylic acids (such as 1–4 ). Because efficient strategies for selectivity control are highly desirable, insights into the major factors controlling both regio- and stereoselectivities in Cu-catalyzed three-component coupling can provide useful guidelines for the development of alkyne difunctionalizations.…”