Synthesis of 1-amino-2-vinylcyclopropane-1-phosphinates. Conversion of a phosphonate to phosphinates

Conversion of diethyl 1-amino-2-vinylcyclopropanephosphonate to ethyl 1-amino-2-vinylcyclopropanephosphinate was accomplished by using either nucleophilic or electrophilic carbon reagents. Hydrolysis of the phosphonate diethyl ester to the mono acid followed by oxalyl chloride treatment provided the phosphonomonochloridate, which was treated with nucleophilic organometallic agents to afford phosphinate ethyl esters. Alternatively, the chloridate was reduced to the phosphonous ethyl ester, and then alkylated with various electrophilic alkylating agents to obtain phosphinate ethyl esters.