Synthesis of α-Aryldiazophosphonates via a Diazo Transfer Reaction.

The simple synthetic procedure for preparation of α-aryl-α-diazophosphonates via a diazo transfer reaction is proposed. Benzylphosphonates reacted with tosyl azide (TsN ₃ ) in the presence of potassium tert -butoxide (KO ^t Bu) to afford diazophosphonates in a yield up to 79%. The proposed method is general. The reaction uses easily available starting materials, tolerates various functional groups, and may be applied for multi-gram scale synthesis.