σ3,λ4-Phosphandiyl-Komplexe: 1,3-Dipolare cycloaddition von Diazomethan an eine Phosphor-Metall-Mehrfachbindung

Abstract The reaction of (2,4,6- t Bu 3 C 6 H 2 O(HCCCH 2 )PMoCp(CO) 2 ( I ) (2,4,6- t Bu 3 C 6 H 2 O  R) with CH 2 N 2 ( II ) gives, via a 1,3-dipolar cycloaddition, the expected compound (R)(HCCCH 2 ) PNN CH 2 M oCp(CO) 2 ( III ), that contains a five-membered cycle of Mo, P, N and C; III can be isolated at low temperature in high yields. When solutions of III are warmed to 25°C, dinitrogen elimination takes place and the three-membered cycle of (R)(CHCCH 2 ) PCH 2 M oCp(CO) 2 ( IV ) is formed. Whereas I reacts with II to form III , no reaction takes place when {(R)[(η 2 -HCCCH 2 )Co 2 (CO) 6 ]}PMoCp(CO) 2 ( VII ) is treated with II . However, the expected product, {(R)[(η 2 -CHCCH 2 )Co 2 (CO) 6 ]} PCH 2 M oCp(CO) 2 ( VI ), can be synthesized by the reaction of IV with Co 2 (CO) 8 V . All new compounds have been identified by elemental analysis and IR, MS, 1 H, 31 P and 13 C NMR spectroscopy.