One-step difunctionalization of [2.2]metacyclophane via its bis(tricarbonylchromium) complex

Abstract

The preparation of 5,13-bisethoxycarbonyl-anti,anti-(µ-[2.2]metacyclophane)bis(tricarbonyl-chromium)(5) in a one-step reaction from ([2.2]metacyclophane)bis(tricarbonylchromium)3 is reported for the first time. Its structure is evaluated on the basis of the ¹³C NMR spectrum and compared with other tricarbonylchromium complexes (2,7). The crystal structure of 5 has been determined. Crystal data: C₂₈H₂₄Cr₂O₁₀, M_r= 624.5; orange blocks; triclinic, space group P; a= 769.0(1), b= 957.4(1), c= 1068.7(1) pm; α= 98.76(1), β= 99.68(1), γ= 102.37(1)°; V= 743.0(3) A³; Z= 1; D_c= 1.396 g cm^–3; crystal dimensions, 0.15 × 0.15 × 0.25 mm³.