Selective preparation of (E)-3-oxo-1-alkenylphosphonates by insertion of acyl chlorides and nitriles into zirconacycles.
Zirconacycles 1, obtained from diethyl 1-alkynylphosphonates, insert either acyl chlorides or nitriles to provide, after acidic workup, (E)-3-oxo-1-alkenylphosphonates, 2, in isolated yields of 55-83%. Insertion produces only one regio- and stereoisomer. The reaction is quite general and proceeds well with both aliphatic and aromatic acyl chlorides. Acetonitrile and p-methoxybenzonitrile also inserted efficiently. Insertion of isobutyl chloroformate produced the vinylphosphonocarboxylate, 2c, the first representative of this class of compounds.
Quntar
Abed Al Aziz
AA
Department of Medicinal Chemistry and Natural Products, School of Pharmacy, Hebrew University in Jerusalem, Jerusalem 91120, Israel.
Melman
Artem
A
Srebnik
Morris
M