Enzymatic process for preparing organosilicon group containing photoinitiators

Abstract

The invention relates to a process for preparing organosilicon group containing photoinitiators of the formula (I), wherein m is a number from 1 to 200; q is 0 or 1; A is IN-C(O)—O—CHR—Y— or IN-C(O)—NH—CHR—Y—; A' is A or R′; Rand R′, Rand R′ are C–Calkyl or phenyl, or —(O)—SiRR′R; Ris hydrogen or C–Calkyl, Y is a divalent group selected from C–Calkeylene, C–Calkenylene or —(CH)—O—(CH)—; and b are each independently of the other a number of 1 to 6; IN is a photolabile functional moiety of the formula (II) or (III), wherein Ris hydrogen or —C(O)—C(O)—OH or —C(O)—C(O)—OC–Calkyl and n is 1–3; Rand Rare C–Calkyl or together are cycloC–Calkyl; Ris hydroxy, C–Calkoxy or morpholinyl; X is —(CH)—, —(CH)—O—(CH)— or —(CH)—O—CO—(CH)—; a and b are each independently of the other a number of 1 to 6; whereby the process is characterized in that a photolabile functional moiety containing a carboxy group (IN-COOH) or an alkoxycarbonyl group (IN-CO—OC–Calkyl) is reacted with a carbinol- or amino terminated organosilicon compound of the formula (IV), wherein m, Rand R′, Rand R′ are as defined above and B is —Y—CHR—OH or —Y—CHR—NH; B′ is B or R′, in the presence of an enzyme which catalyzes the esterification, transesterification or amidation reaction.