Synthesis of P-chiral phosphine compounds by palladium-catalyzed C-P coupling reactions.

An efficient C-P coupling reaction of enantiopure tert-butylmethylphosphine-boranes with aryl and heteroaryl halides is developed by using Pd(OAc)2/dppf as a catalyst, affording a series of (S) or (R)-P-chiral phosphines in moderate to high yields and with ee values up to 99% ee. Moreover, the reaction time could be reduced from 72 h to 6 h with increased ee values under microwave irradiation.

Transition-Metal-Catalyzed Regioselective Functionalization of Monophosphino-o-Carboranes.

A facile approach to the synthesis of diaryl- and dialkyl-substituted monophosphino-o-carboranes by rhodium(I)-catalyzed phosphine-directed B3,6 -H activation has been developed for the first time. Upon switching rhodium(I) to palladium(II), C-arylated and B6 -halogenated products were obtained by using tBuOLi and Li2 CO3 as base, respectively. These discoveries provide some simple and efficient approaches to the modification of monophosphino-o-carboranes.

Visible-Light-Promoted Transition-Metal-Free Phosphinylation of Heteroaryl Halides in the Presence of Potassium tert-Butoxide.

A novel visible-light-promoted C-P bond formation reaction in the absence of both transition metal and photoredox catalysts is disclosed. By employing easily available and inexpensive heteroaryl chlorides/bromides as substrates, a variety of heteroaryl phosphine oxides were obtained in moderate to good yields. This strategy provides a simple and efficient route to heteroaryl phosphine oxides.

Synthesis of peri-Substituted (Naphthalen-1-yl)phosphine Ligands by Rhodium(I)-Catalyzed Phosphine-Directed C-H Arylation.

A novel protocol for effective rhodium(I)-catalyzed C-H arylation of tertiary phosphines has been devised. It is amenable to a wide range of substrates and gives the products in moderate to high yields. This strategy provides a simple and efficient route to peri-substituted (naphthalen-1-yl)phosphines.