Alcohols and amines are widely used for their valuable applications in organic synthesis as well as pharmaceuticals. The conventional methods reported for C-N or C-C bond formation, generally incorporates environmentally toxic alkyl/aryl halide with amines and alcohols.[1] This talk discusses an alternative route for the synthesis of C-N formation using alcohol as an alkyl precursor.[2] The use of a various (R2NNN)RuCl2(L) (R = tBu, iPr, Cy and Ph; L = PPh3 and CO) pincer complexes in catalyzing the N-alkylation of primary amine with primary alcohol or C-alkylation of secondary alcohol with primary alcohol incites great interest.[3] Turnover numbers (TON) up to 29000 were obtained at 140 °C for the NNN pincer-Ru catalyzed N-alkylation. On the other hand, the same type of pincer catalysts (R2NNN)RuCl2(L) (R = tBu, iPr, Cy and Ph; L = PPh3 and CO) in the presence of only 2.5 mol % of NaOH provided up to 388000 TON for C-alkylation of secondary with primary alcohols. Sterically more open pincer-ruthenium complexes such as (Bim2NNN)RuCl2(CO) based on, 2,6-bis(benzimidazole-2-yl) pyridine ligand, demonstrated not only good selectivity towards ethanol to butanol upgradation but also gave 58% ethanol conversion along with high turnovers (ca. 2100, TOF; 710 TOh-1). Detailed kinetic studies indicate that the reaction rate has first order dependence on the concentration of both catalyst and ethanol.

Pincer-Ruthenium catalyzed production of biofuels and value-added chemicals via alkylation of amines and alcohols

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.