Portal de Periódicos da CAPES

Reactions of bicyclic cyclopropanes and bicyclic cyclobutanes with dichlorobis(benzonitrile)palladium(II)

1981; Elsevier BV; Volume: 214; Issue: 2 Linguagem: Inglês

10.1016/s0022-328x(00)86635-8

1872-8561

Michael F. Rettig, Dean E. Wilcox, R. Fleischer,

Metal-Catalyzed Oxygenation Mechanisms

Exo- and endo-9-methylbicyclo[6.1.0]non-4-enes react with dichlorobis(benzonitrile)palladium(II) to produce initially the isomeric dimeric (chlorine bridged) π-complexes, (PdCl2 - C10H16)2. The π-complexes rearrange within minutes in solution at room temperature to produce stereospecifically the chlorine bridged dimeric trihapto-σ,π-cyclooctenyl complexes which result from chloropalladation of the external cycopropane carbon—carbon bond, with chlorine bound at the carbon bound to methyl. The chloropalladations also occur during several hours at 75°C in the solid state. The σ,π-cyclooctenyls react with cyanide ion to produce quantitatively 9-methyl-trans-bicyclo[6.1-0]non-4-ene, which hydrocarbon was also independently synthesized. The trans-fusion in the product of cyanide displacement implies an inversion at carbon along the reaction pathway. The relationship of this chemistry to cyclopropane oxymercuration is discussed. The cyclobutane containing hydrocarbon bicyclo[6.2.0] dec-4-ene was incorporated in a π-complex similar to those above. The cyclobutane moiety was found to be inert to chloropalladation under mild to moderate conditions.