Wide bite angle diphosphine rhodium complexes: Synthesis, structure, and catalytic 1,4-addition of arylboronic acids to enones

Aryl Ether Cleavage by Group 9 and 10 Transition Metals: Stoichiometric Studies of Selectivity and Mechanism

“…(Scheme ). Resonances at 3.07 ppm (major isomer) and 3.02 ppm (minor isomer) in the 1 H NMR spectrum are attributable to the −OC H 3 substituent of 1a remaining intact in 23a , assigned as a diphosphine Rh­(Cl)­(CO) species with an IR stretch assigned to Rh–CO (ν CO = 1957 cm –1 ) comparable to those reported in the literature for similar compounds. , Heating a solution of 23a in a sealed J. Young tube affords the new compound 24a with a new resonance observed by 31 P NMR spectroscopy (43.34 ppm) and an IR stretch (ν CO = 1942 cm –1 ) comparable to those of previously reported phenoxide diphosphine RhCl species .…”