138614-14-9Relevant academic research and scientific papers
Synthesis of N-bonded enolatoruthenium(II) by oxidative addition of alkyl cyanocarboxylate to a ruthenium(0) complex
Hirano, Masafumi,Takenaka, Atsushi,Mizuho, Yuji,Hiraoka, Makiko,Komiya, Sanshiro
, p. 3209 - 3216 (2007/10/03)
Reaction of a zero-valent ruthenium complex [Ru(cot)(cod)] 1 (cod = 1,5-cyclooctadiene; cot = 1,3,5-cyclooctatriene) with alkyl cyanoacetate in the presence of mono- and bi-dentate tertiary phosphines gave a series of hydrido(enolato)-ruthenium(n) complexes: mer-[RuH(NCCHCO2Et)(NCCH2CO2Et)(PPh 3)3] 2; trans-[RuH(NCCHCO2Et)(cod)-(dppe)] 3 (dppe = Ph2PCH2CH2PPh2); trans-[RuH(NCCR1CO2R2)(dppe)2] (R1 = H, R2 = Et 4a: or Pri 4b; R1 = Me, R2 = Et 4c) and trans-[RuH(NCCMeCO2Et)(PMePh2)4] 5. The molecular structure of 3 shows that the enolato ligand co-ordinates to the ruthenium centre via the cyano group in an octahedral geometry. These hydrido-(enolato)ruthenium(II) complexes catalyse Michael and Knoeevenagel reactions under neutral and mild conditions. The Royal Society of Chemistry 1999.
Ruthenium-catalyzed aldol and Michael reactions of nitriles. Carbon-carbon bond formation by α-C-H activation of nitriles
Murahashi, Shun-Ichi,Naota, Takeshi,Taki, Hiroshi,Mizuno, Masahiko,Takaya, Hikaru,Komiya, Sanshiro,Mizuho, Yuji,Oyasato, Naohiko,Hiraoka, Makiko,Hirano, Masafumi,Fukuoka, Atsushi
, p. 12436 - 12451 (2007/10/03)
The ruthenium(II)-catalyzed reaction of nitriles with carbonyl compounds proceeds highly efficiently under neutral and mild conditions to give α,β-unsaturated nitriles. Under similar reaction conditions, nitriles react with olefins bearing electron-withdrawing groups to give the corresponding Michael adducts. The efficiency of the reaction is illustrated by the selective additions to α,β-unsaturated aldehydes and acetylenes bearing electron-withdrawing groups, which are difficult to perform using conventional bases. Chemoselective aldol and Michael reactions of nitriles can be performed in the presence of other active methylene compounds. Tandem Michael and Michael-aldol condensations of nitriles 30 can be performed with high diastereoselectivity. These reactions can be rationalized by assuming oxidative addition of ruthenium(0) to the α-C-H bond of nitriles and subsequent insertions to carbonyl compounds or olefins. As the key intermediates and active catalysts hydrido(N-bonded enolato)ruthenium(II) complexes, mer-RuH(NCCHCO2R)(NCCH2CO2R)(PPh3)3 (R = Me (41a), Et (41b), n-Bu (41c)) have been isolated upon treatment of RuH2(PPh3)4 (3) or RuH(C2H4)(PPh3)2(PPh2C6H4) (4) with alkyl cyanoacetates. Kinetic study of the catalytic aldol reaction of ethyl cyanoacetate with benzaldehyde indicates that the rate-determining step is the reaction of enolato complex 41 with aldehydes.
