Rhodium-catalyzed oxidative coupling through C–H activation and annulation directed by phosphonamide and phosphinamide groups

Abstract

Rhodium-catalyzed oxidative coupling reactions via C-H activation and annulation directed by phosphonamide and phosphinamide groups were developed under aerobic conditions, which produced benzazaphosphole 1-oxides and phosphaisoquinolin-1-oxides.

Rhodium Catalyzed ortho‐Cyanation of Arylphosphates with N‐cyano‐N‐phenyl‐p‐toluenesulfonamide

“…To shed more light on the reaction mechanism, a deuterium‐labeling experiment was were performed (Scheme ) 12. 16a When a 1:1 mixture of 1 a and 1 a‐[D 5 ] was subjected to the Rh‐catalyzed reaction conditions, we obtained the cyanation products 3 a and 3 a‐[D 4 ] in a ratio of 4.9:1. This kinetic isotope effect (KIE) value of 4.9 is typical of Rh‐catalyzed CH activation processes.…”

Late stage modifications of P-containing ligands using transition-metal-catalysed C–H bond functionalisation

“…During their investigation on annulation reaction between phosphonamide and activated alkenes or alkynes, Lee and coworkers also demonstrated that phosphonamide can act as a directing group in Rh(III)-catalysed ortho-alkenylation with styrenes even in the presence of TEMPO (Scheme 10). 18 The reaction was found to be sluggish with non-activated alkenes and only mono-alkenylation occurred even in the presence of access amount of styrene derivatives. In 2017, our group reported the first example of orthoalkenylation with alkenes of triarylphosphine oxides using Ru(II) catalyst (Scheme 11).…”

Rhodium‐Catalyzed Oxidative C–H Activation/Cyclization for the Synthesis of Phosphaisocoumarins and Phosphorous 2‐Pyrones

“…Encouraged by the our previous results,4b the most efficient catalysis was achieved with alkenylphosphonic monoesters, which also allowed the synthesis of phosphorus 2‐pyrones (Scheme ).…”