Abstract
Mn(CO) 5 (η 1 -pentadienyl) (1) and the corresponding η 1 -hexadien-1-yl complex (2) undergo [4 + 2] cycloaddition with tetracyanoethylene and maleic anhydride to produce the adducts (CO) 5 MnCH 2 -CHC(CN) 2 C(CN) 2 CH(R)CH=CH 2 (R = H (3), CH 3 (4)) and (CO) 5 MnCH 2 -CHCHCOOCOCHCHRCH=CH (R = H (5), CH 3 (6)). The anhydride adducts 5 and 6 undergo further intramolecular carbonylation to give the acyl complexes (CO) 4 MnCOCH 2 CHCHCOOCOCHCHRCH=CH (R = H (7), CH 3 (8)). For the η 1 -5-methyl-2,4-hexadien-1-yl complexes M(η 1 -CH 2 CH=CHCH=C(Me) 2 ) (M = Mn(CO) 5 (9), CpFe(CO) 2 (10), CpMo(CO) 3 (11)), cycloaddition of each complex with tetracyanoethylene gives the [3 + 2] cycloadduct M(CHCH(CH=CMe 2 )C(CN) 2 C(CN) 2 CH 2 ) (M = Mn (CO) 5 (12), CpFe(CO) 2 (13), CpMo(CO) 3 (14)) in moderate yields. X-ray diffraction studies of 4 and 14 were undertaken. Crystallographic data for 4: space group Pbca; a = 13.353 (3) Å, b = 19.010 (4) Å, c = 14.437 (3) Å; V = 3664.6 Å 3 ; Z = 8; R F = 3.7, R w = 2.4. For 14: space group P2 1 /n; a = 10.760 (8) Å, b = 15.898 (6) Å, c = 12.57 (4) Å, β = 96.97 (14) Å; V = 2134.54 Å 3 ; Z = 4; R F = 3.9, R w = 4.3. © 1989 American Chemical Society.