| abstract |
In the process for the preparation of 1,4-diphenylazetidinone derivatives from suitably protected β-substituted aminoamides in the presence of silylating agents, cyclizing catalysts bearing cation (XII), phosphonium ions and anions (b) or (b) general are used ) or (c) or (d), wherein the symbols, substituents and markers have the following meanings: Z = C = O, C = S, S = O, SO2 or C = NR20, K = O, S, NR21 or CR22R23, L = NR24 or CR25R26, n = 0 or 1, M = O, C = O, NR27 or CR28R29, Q = O, S, NR30, CR31R32, C = O, C = S, S = O, SO2 or C = NR34, R = CR35 or N, T = CR36 or N, U = CR37 or N, V = CR38 or N, and wherein the radicals R16 to R19 are may mean, for example, aryl or (C1-C15) alkyl, aryl- (C1-C10) alkylene, and radicals R20 to R32 and R34 to R38 may additionally mean H or heteroaryl; R39 and R40 are for example (C1 -C6) alkyl. The anion may also be R41O¯, R42COO¯ or C¯¯, Br¯, or Ig (in combination with Ag20). |