1,3-Dipolar Cycloaddition Reactions of Low Valent Metal-Carbonyl Complexes with Arylnitrile-N-Oxides

摘要

Several low valent metal carbonyl complexes are reported to react with arylnitrile-N-oxides for form (O-N=(Ar)C-M-C(O)) from a 1,3-dipolar cycloaddition of arylinitrile-N-oxide to a M-C(O) bond. Complexes (Et4N)((Ph3P)(CO)RhC2B9H11)(1a;3,1,2 isomer and 1b; 2,1,7 isomer) react with benzonitrile-N-oxide to produce cycloadducts 2a and 2b, respectively. Similarly K(18-crown-6) la and (Et4N) lb react with m-fluorobenzonitrile-N-oxide to produce 3a and 3b, respectively. Analytical and spectral characterization of the new cycloadducts was supported by the X-ray diffraction study of the (PPN) + salt of 3b. Reactions of the cycloadducts with CO are described. The complexes K(18-crown-6)M(CO)5(M=Re, Mn) react with benzonitrile -n-oxide to produce cycloadducts 5a and 5b, respectively. Complex 5 a is quite stable, but 5b is exceedingly unstable. (N-5-C5(CH3)5) Rh(CO)2 reacts with p-chlorobenzo-nitrile-N-Oxide to produce an intermediate cycloadduct, 8, which can be converted to the known dimeric complex ((N5-C5(CH3)5)Rh(micron-CO))2.