SYNTHESIS AND REACTIVITY OF IRON CARBONYL-COMPLEXES OF BETA-SILYL SUBSTITUTED ALPHA,BETA-UNSATURATED KETONES

beta-Silyl alpha,beta-unsaturated ketones, R(3)SiCH=CHC(O)Me (R(3)Si = Me(3)Si, Bu(t)Me(2)Si, PhMe(2)Si), react with [Fe-2(CO)(9)] at 35 deg rees C in diethyl ether to give tetracarbonyl[R(3)SiCH=CHC(O)Me]iron(0 ) complexes and at 55 degrees C in toluene to give tricarbonyl[R(3)SiC H=CHC(O)Me]iron(0) complexes. Tricarbonyl[Me(3)SiCH=CHC(O)Me]iron(0) a nd tricarbonyl[Bu(t)Me(2)SiCH=CHC(O)Me]iron(o) react with methyllithiu m under a nitro gen atmosphere to give hexane-2,5-dione and 3-(tert-bu tyldimethylsilyl)hexane-2,5-dione, respectively, and with methyllithiu m under a carbon monoxide atmosphere to give the vinylketene complexes methyl-5-trimethylsilyl-1-oxa-1,2,4-triene)iron(0) and thylsilyl-3-me thyl-1-oxapenta-1,2,4-triene)iron(0) respectively.