New Pd‐phosphorus ylide complexes based on FC60 as heterogeneous nano‐catalyst for H/D exchange reaction

Abstract

In this account, new Pd(0) complexes of phosphorus ylides based on fullerene C60 (FC60) were synthesized and utilized as the first fullerene‐based heterogeneous nano‐catalysts for H/D exchange reaction. Four new palladacyclopropa‐[60]fullerene complexes 1–4, [(η2‐C60)Pd(Y1–4)2] (Y1 = PPh3CHC(O)C6H4‐p‐NO2, Y2 = PPh3CHC(O)C6H4‐p‐CH3, Y3 = (p‐tolyl)3P‐CHC(O)C6H4‐p‐NO2, and Y4 = (p‐tolyl)3P‐CHC(O)C6H4‐p‐CH3), were prepared through dissolving the related α‐keto stabilized phosphorus ylide in toluene solution in the presence of FC60 and Pd (dba)2 (dba = dibenzylideneacetone). All of the complexes were characterized using Nuclear magnetic resonance (NMR) (1H, 13C, and 31P), Infrared spectroscopy (IR), Ultraviolet‐visible spectroscopy (UV‐visible), fluorescence, Electrospray Ionisation Mass Spectrometry (ESI‐MS), and Energy‐dispersive X‐ray spectroscopy (EDX) spectroscopies, and scanning electron microscopy (SEM) and TEM techniques. The data proved that FC60 and two ylides were coordinated to Pd(0) center through two hexagons and two ylidic carbon atoms, respectively. An evaluation was also performed to compare the catalytic activity of synthesized Pd complex 1 and a conventional heterogeneous catalyst, 10% Pd on carbon, in H/D exchange reaction. The results indicate that the process of H/D exchange reaction in aromatic rings of benzoic acid derivatives progressed more efficiently by Pd complex 1.