Direct Palladium-Catalyzed Carbonylative Transformation of Allylic Alcohols and Related Derivatives

Abstract

A direct, palladium-catalyzed, carbonylative transformation of allylic alcohols for the synthesis of β,γ-unsaturated carboxylic acids has been developed. With formic acid as the CO source, various allylic alcohols were conveniently transformed into the corresponding β,γ-unsaturated carboxylic acids with excellent linear and (E)-selectivity. The reaction was performed under mild conditions; toxic CO gas manipulation and high-pressure equipment were avoided in this procedure.

Revisiting the Palladium-Catalyzed Carbonylation of Allyl Alcohol: Mechanistic Insight and Improved Catalytic Efficiency

“…The species 2 subsequently rearranges to the alkyl-Pd II intermediate 3. 13 Based on the 1 H NMR analysis results at different time intervals and the proposed mechanism, the final step of the Pdcatalyzed carbonylation of allyl alcohol to CA involves the isomerization of 3-butenoic acid to CA. Therefore, the isomerization of 3-butenoic acid to CA was then studied using Pd(OAc) 2 /dppb as the catalyst.…”

“…The oxidative addition of allyl alcohol to the Pd 0 species 1 leads to the (π-allyl)palladium intermediate, 2 , thus activating the C–O bond in the allyl alcohol. The species 2 subsequently rearranges to the alkyl-Pd II intermediate 3 . Then, the coordination and insertion of CO with 3 lead to the formation of the Pd-acyl intermediate 4 .…”

“…However, the poor leaving ability of the hydroxyl group and the H 2 O byproduct causes poor selectivity, leading to the formation of a mixture of products including unsaturated acids, butenoic acid derivatives, cyclized lactones, and unsaturated esters (Scheme S1). − Thus, the carbonylation of allyl alcohol derivatives, in general, suffers from obvious drawbacks, such as high CO pressures, poor selectivity, or/and low yield. Interestingly, Alper et al reported the selective carbonylation of allyl alcohol to CA in 93% yield with a turnover number (TON) of 23.3 using Pd­(dba) 2 (dba = bis­(dibenzylideneacetone)) and 1,4-bis­(diphenylphosphino)­butane (dppb) as a catalytic system at 190 °C for 48 h under 40 bar CO in dimethoxyethane (DME) .…”

Direct synthesis of benzylic amines by palladium-catalyzed carbonylative aminohomologation of aryl halides

“…28 Recently, we have developed a series of palladiumcatalyzed carbonylation reactions with formic acid as a green CO source. 29,30 In addition, we reported a palladium-catalyzed reductive carbonylation of aryl halides for the synthesis of aromatic aldehydes with formic acid as both CO source and reductant. Since formic acid is also widely used as a useful hydrogen surrogate, we propose that the direct carbonylationbased aminomethylation could be realized from aryl halides and amines in the presence of formic acid.…”

Nickel-catalysed carbonylative homologation of aryl iodides

“…Additionally, Ni(CO) 4 has limited reactivity in oxidative addition with substrates, due to the full coordination of CO on the metal center. Based on our previous experience in developing new CO-gas-free carbonylation reactions [21][22][23][24][25][26][27] , we assume the usage of Mo(CO) 6 as a solid CO source could be an ideal option for exploring nickel catalyst in carbonylation chemistry 28,29 .…”