Synthesis 2020; 52(16): 2410-2426
DOI: 10.1055/s-0040-1707104
paper
© Georg Thieme Verlag Stuttgart · New York

Alkylation of Phosphinite/Phosphonite-Boranes via Temporary Protection of the P–H Bond

Kamil Modzelewski
,
Sylwia Sowa
Department of Organic Chemistry, Faculty of Chemistry, Institute of Chemical Sciences, Marie Curie-Sklodowska University in Lublin, 33 Gliniana St., Lublin 20-614, Poland   Email: sylwia.sowa@poczta.umcs.lublin.pl
› Author Affiliations
Further Information

Publication History

Received: 04 January 2020

Accepted after revision: 06 April 2020

Publication Date:
22 June 2020 (online)


Abstract

A new alkylation protocol for the synthesis of tertiary phosphonite­/phosphinite-boranes is developed. P-Alkylation products are obtained exclusively in moderate to very good yields from easily accessible (1-hydroxy-1-methylethyl)/(1-hydroxy-1-cyclohexyl) phosphonite/phosphinite-boranes upon reaction with a variety of electrophiles under mild conditions. The methodology opens up new synthetic routes for organophosphorus chemistry and offers access to valuable alkyl phosphonite/phosphinite-boranes. In contrast to previously reported oxidative removal–substitution sequences for the preparation of optically active phosphinite-boranes, our protocol provides a one-step procedure that occurs without loss of stereochemical information at phosphorus. This new approach provides a rather advantageous protocol when compared to direct alkylation methods (which may undergo P-epimerization) and occurs in a stereoselective manner even at 0 °C.

Supporting Information