Copper-Catalyzed Carboxylation of Hydroborated Disubstituted Alkenes and Terminal Alkynes with Cesium Fluoride

Abstract

A protocol for the hydrocarboxylation of disubstituted alkenes and terminal alkynes providing access to different secondary carboxylic acids and malonic acid derivatives has been developed. This methodology relies on an initial hydroboration using 9-BBN followed by carboxylation with carbon dioxide in the presence of a copper catalyst and the additive, cesium fluoride. Different cyclohexene, styrene, and stilbene derivatives could be utilized, and alkynes could be transformed into their corresponding dicarboxylic acids in good yields. Finally, six different terpenoids were carboxylated using the developed procedure.

Beneficial Effect of a Secondary Ligand on the Catalytic Difunctionalization of Vinyl Arenes with Boron and CO2

“…4‐isobutylstyrene ( 1 e ) and 3‐phenyoxystyrene ( 1 m ) were synthesized by subjecting the commercially obtained aldehyde precursor to Wittig conditions . 2‐methoxy‐6‐vinylnaphthalene ( 1 l ) and 3‐fluoro‐4‐phenylstyrene ( 1 n ) were prepared by performing Suzuki cross‐coupling between commercially available aryl bromide and vinyl‐Bpin. The preparation and isolation of ICyCuCl complex was based on literature precedent …”

New trends and applications in carboxylation for isotope chemistry

“…The Skrydstrup group (Scheme 22) have developed a method to carboxylate benzyl-9-borabicyclononane (benzyl-9-BBN) compounds using copper(I) catalysis (Scheme 22). 36 Using 2 equivalents of CO 2 and [(IPr) CuF] formed in situ from CuI, 1,3-bis-(2,6diisopropylphenyl)imidazolinium, and 3 equivalents of CsF, they demonstrated that styrenes and stilbenes could be successfully carboxylated (via the benzyl-9-BBN adduct). The reaction was run at elevated temperatures and tolerated a wide range of substrates including phosphonates, thioethers, boronic acids, halides, and methylindoles.…”

“…The methodology of Skrydstrup reported in Section 4.2.2 has also been applied to affect the carboxylation of primary and secondary alkyl‐9‐BBN compounds (Scheme ) . The regioselectivity of the carboxylation is determined by the regiochemistry of the boronic acid.…”

Computational and Experimental Insights into Asymmetric Rh‐Catalyzed Hydrocarboxylation with CO2

“…A significant part of this activity is focused on metal‐catalyzed carbon‐carbon bond formation with CO 2 [2] . For the metal‐catalyzed formation of saturated carboxylic acids, different protocols have been reported, including carboxylation of halides (C−X bonds) [2a,b] and reductive carboxylation of unsaturated compounds such as alkenes [2c–h] . An example of the carboxylation of Csp 3 −X bonds has been reported by Martin and co‐workers, who developed a mild Ni(I)‐catalyzed protocol for converting benzyl halides and CO 2 to phenylacetic acids [2b] .…”