Cooperative catalytic methoxycarbonylation of alkenes: uncovering the role of palladium complexes with hemilabile ligands

Palladium-catalysed methoxycarbonylation of ethene with bidentate diphosphine ligands: a density functional theory study

The mechanism and origin of selectivity of Pd-catalysed formation of methyl propionate is elucidated through DFT calculations.

Direct synthesis of adipic acid esters via palladium-catalyzed carbonylation of 1,3-dienes

The direct carbonylation of 1,3-butadiene offers the potential for a more cost-efficient and environmentally benign route to industrially important adipic acid derivatives. However, owing to the complex reaction network of regioisomeric carbonylation and isomerization pathways, a selective practical catalyst for this process has thus far proven elusive. Here, we report the design of a pyridyl-substituted bidentate phosphine ligand (HeMaRaphos) that, upon coordination to palladium, catalyzes adipate diester formation from 1,3-butadiene, carbon monoxide, and butanol with 97% selectivity and 100% atom-economy under industrially viable and scalable conditions (turnover number > 60,000). This catalyst system also affords access to a variety of other di- and triesters from 1,2- and 1,3-dienes.

Pd-Catalyzed Selective Carbonylation of gem-Difluoroalkenes: A Practical Synthesis of Difluoromethylated Esters

The first catalyst for the alkoxycarbonylation of gem-difluoroalkenes is described. This novel catalytic transformation proceeds in the presence of Pd(acac)₂ /1,2-bis((di-tert-butylphosphan-yl)methyl)benzene (btbpx) (L4) and allows for an efficient and straightforward access to a range of difluoromethylated esters in high yields and regioselectivities. The synthetic utility of the protocol is showcased in the practical synthesis of a Cyclandelate analogue using this methodology as the key step.

Development of efficient palladium catalysts for alkoxycarbonylation of alkenes

Herein, we report a general and efficient Pd-catalysed alkoxycarbonylation of sterically hindered and demanding olefins including a variety of tri-, tetra-substituted and 1,1-disubstituted alkenes. In the presence of 1,3-bis(tert-butyl(pyridin-2-yl)phosphanyl)propane L3 or 1,4-bis(tert-butyl(pyridin-2-yl)phosphanyl)butane L4 the desired esters are obtained in good yields and selectivities. Similar transformation is obtained using tertiary ether as showcased in the carbonylation of MTBE to the corresponding linear ester in high yield and selectivity.