Process for the preparation of bis(acyl)phospinic acid sylyl esters

A process for the preparation of a bis(acyl)phosphinic acid silyl ester of the general formula I:

• wherein R1, R2, R3, R4, R5, R7, R8, R9, R10 and R11 are the same or different and are independently selected from H, halogen, linear or branched C1-C20-alkyl, linear or branched C2-C8-alkenyl, C1-C8-alkoxy, C2-C8-alkenyloxy, C3-C8-cycloalkyl, C6-C12-aryl, C3-C8-cycloalkoxy, C7-C12-arylalkoxy, C9-C15-alkenylarylalkoxy, nitro-, C6-C12-arylsulfonyl, 4-alkylarylsulfonyl, C1-C20-alkylcarboxy, C1-C8-alkoxycarbonyl, SR12, NHR12 or NR12R13 with R12 and R13 being independently selected from H, linear or branched C1-C20-alkyl, linear or branched C2-C8-alkenyl and C3-C8-cycloalkyl, and an O-, S- or N-containing 5- or 6-membered heterocyclic ring;
• R6 is OSiR14R15R16 with R14, R15 and R16 being independently selected from linear or branched C1-C20-alkyl or C6-C12-aryl,
• the process comprising the steps of
• a) heating ammonium hypophosphite with a silylating agent for obtaining a bis(silyl ether)phosphine, and
• b) reacting the bis(silyl ether)phosphine obtained in step a) with a compound of the general formula IIa and/or IIb,
• wherein R1, R2, R3, R4 and R5 and/or R7, R8, R9, R10 and R11 are as defined above;
• Z is halogen.