A General Strategy for the Synthesis of P-Stereogenic Compounds

摘要

Preparing P-stereogenic compounds is one of the biggest challenges of organophosphorus chemistry. Although various methods have been reported for the preparation of specific P-stereogenic building blocks, based on kinetic resolution, or on chiral auxiliaries, typically these have severe limitations in the scope of their application. More than 40 years ago, Mislow and others pioneered the field of P-stereogenic compounds and the study of their reactivities. A case in point is menthyl phenyl-H-phosphinate PhP(O)-(OMen)H (1), which has since been employed in various reactions such as cross-coupling, substitution, or hydrophos-phinylation. However, enriched diastereomers of 1 remain difficult to prepare as their isolation requires low-temperature recrystallization (multiple crystallizations below -30°C or at -70°C), and yields of isolated products were not reported. Similar chemistry using MenOPCl2 and aryl Grignard reagents was reported recently. In the final analysis, these methods still require cumbersome crystallization procedures and are limited in terms of the phosphorus compounds that are accessible and therefore the final products (usually P-stereogenic phosphines) that can be derived from them.