ACTIVATION OF PROP-2-YN-1-OLS BY METAL-CARBONYLS - SYNTHESIS OF (ALKOXYALKENYLCARBENE) AND (AMINOALKENYLCARBENE)CHROMIUM AND (AMINOALKENYLCARBENE)TUNGSTEN COMPLEXES

Fischer type methoxyalkenylcarbene complexes (CO)(5)M=C(OMe)(C H=CRR') have been prepared in one step by photolysis of M(CO)(6) [M = Cr, W] in tetrahydrofuran-methanol, in the presence of prop-2-yn-1-ol derivat ives HC=CC(OH)(R)(R') [R, R' = Me; R = H, R' = Me, Ph, C6H4-p-NMe(2)]. Photolysis of a tetrahydrofuran-methanol solution of M(CO)(6) with HC =CC(OH)(H){(CH=CH)(n)CH=CRR'} [n = 0 R, R' = Me; R = H, R' = H, Me, Ph , C6H4-p-NMe(2), C5H11; n = 1 R = H, R' = Me] provides the new dienyl- and trienylcarbene complexes (Co)(5)W=C(OMe)(CH=CHCH=CRR') and (CO)(5 )M=C(OMe)(CH=CHCH=CHCH=CHMe) in 30-70% yields. Alkoxyalkenylcarbene co mplexes (CO)(5)M=C(OCH(2)Z)(CH=CRR') are prepared analogously by using other primary alcohols ZCH(2)OH [Z = CH2CH(Me)(Et), CH2-CH2C=CMe, CH2 CH2CH=CH2, CH2CH2C(Me)=CH2. [(Alkenyloxy)alkenylcarbene]tungsten compl exes undergo smooth thermal intramolecular cyclopropanation reactions leading to 1-alkenyl-2-oxabicyclo[3.1.0]hexane compounds. Finally, a s eries of aminodienylcarbene complexes (CO)(5)W=C(NHR')(CH=CHCH=CHR) [R = Ph, C5H11; R' = CHMe(2), CMe(3), CH2CH=CH2, CH(2)CHMe(2)] have been synthesized by aminolysis of the corresponding methoxydienyl carbenes .