178687-70-2Relevant articles and documents
Cyclopropenation and related reactions of ruthenium vinylidene complexes
Ting, Pei-Chen,Lin, Ying-Chih,Lee, Gene-Hsiang,Cheng, Ming-Chu,Wang, Yu
, p. 6433 - 6444 (1996)
Facile deprotonation of a number of cationic ruthenium vinylidene complexes, followed by cyclopropenation, is accomplished in acetone. The deprotonation of [Ru]=C=(Ph)CH2R+, ([Ru] = (η5-C5H5)(PPh3)2Ru) by n-Bu4NOH induces a novel cyclization reaction and yields the neutral cyclopropenyl complexes [Ru]-C=C(Ph)CHR (3b, R = CN; 3c, R = Ph; 3d, R = CH=CH2; 3e, R = CH=CMe2). Complex [Ru]-C=C(C6H9)CHCN+ (3k) is similarly prepared. Protonation of 3b-3e regenerates the corresponding vinylidene complexes. Deprotonation of [Ru]=C=C(Ph)CH2COOMe+ (2h) by n-Bu4NOH induces a different type of cyclization and yields the neutral furan complex [Ru]-C=C(Ph)CH=C(O)OMe (4h). The cyclopropenyl complex containing a methoxy substituent cannot be prepared from [Ru]=C=C(Ph)CH2OCH3+ (2i), but F- of n-Bu4NF attacks the C(α) of 2i to produce the unstable vinyl complex [Ru]C(F)=C(Ph)CH2OCH3 (5). Complex [Ru]-C=C(Ph)C(CN)OCH3 (9b) was indirectly prepared from the addition of TCNQ to 3b, giving [Ru]=C=C(Ph)CH(CN)TCNQ (6b) followed by methanolysis. Unlike 3, complex 9b is not converted to vinylidene complex, instead, removal of the methoxy substituent by acid gives the cationic cyclopropenylium complex [Ru]-C=C(Ph)G(GN)+ (10b). Complex [Ru]-C=C(Ph)C(COOMe)+ (10h) is similarly prepared from 4h via a TCNQ complex 6h followed by a methoxy-substituted complex 9h. In the presence of allyl iodide, opening of the three-membered ring of 3b, followed by a subsequent oxidative coupling reaction, gives a dimeric dicationic product {[Ru]=C=C(Ph)-CHCN}22+ (11). Proton abstraction of 11 by n-Bu4-NF gives the biscyclopropenyl complex {[Ru]-C=C(Ph)CCN}2 (12). Molecular structures of complexes 3b, 3f, 4h, 6b, 9b, and 11 have been confirmed by X-ray diffraction analysis.
