503584-78-9Relevant academic research and scientific papers
Intramolecular [2 + 2] cycloaddition of allyl C=C and allenylidene C α=Cβ bonds: Formation and deprotonation of cyclobutylidene rings
Diez,Gamasa,Gimeno,Lastra,Villar
, p. 1410 - 1418 (2008/10/09)
The mixed-phosphine complex [Ru(η5-C5H 5)Cl{k1(P)-Ph2PCH2CH=CH 2}(PPh3)] (1) has been prepared by a phosphine exchange reaction between [Ru(η5-C5H5)Cl(PPh 3)2] and Ph2PCH2-CH=CH2 (ADPP) (1:1 molar ratio) in refluxing THF. The treatment of complex 1 with NaPF6 in refluxing ethanol affords diastereoselectively the cationic complex [Ru(η5-C5H5){k3(P,C,C)- Ph2PCH2CH=CH2}(PPh3)][PF 6] (2b). The reaction of complexes [Ru(η5-C 9H7){k3(P,C,C)-Ph2PCH 2CH=CH2}(PPh3)][PF6] (2a) and 2b with propargyl alcohols HC≡CC(OH)R1R2 (R1 R2 -C12H8; R1 = Ph, R2 = Ph, H, Me) in refluxing THF yields regio- and diastereoselectively the cyclobutylidene complexes [Ru(η5-CnH m){k2(P,C)-{=CCH(CH2PPh2)CH 2C=CR1R2}}(PPh3)]-[PF6] (CnHm = C9H7, R1, R 2 = C12H8 (3a), R1 = Ph, R 2 = Ph (3b), H (3c), Me (3d); CnHm = C 5H5, R1, R2 = C12H 8 (4a), R1 = Ph, R2 = Ph (4b), H (4c)). The formation of complexes 3a-d and 4a-c proceeds through an intramolecular cycloaddition of the C=C allyl and Cα=Cβ bonds in the intermediate allenylidene complexes [Ru(η5-C nHn)(=C=C=CR1R2){k 1(P)-Ph2PCH2CH=CH2}(PPh 3)][PF6]. The allenylidene complex [Ru(η5- C9H7)(=C=C=CPh2){k1(P)-Ph 2PCH2CH=CH2}(PPh3)][PF6] (5) has been isolated from the reaction of 2a with 1,1-diphenyl-2-propyn-1-ol in CH2Cl2. The deprotonation of complexes 3a-d and 4a with potassium tert-butoxide gives rise to the neutral complexes [Ru(η 5-CnHm){k2(P,C)-{C=C-(CH 2PPh2)CH2C=CR1R2}} (PPh3)] (CnHm = C9H7, R1; R2 = C12H8 (6a), R1 = Ph, R2 = Ph (6b), H (6c), Me (6d); CnHm = C5H5, R2 = Ph, R2 = H (7c)). The structures of derivatives 3a and 6d have been determined by single-crystal X-ray diffraction analysis.
Diastereoselective synthesis of the indenylruthenium(II) complexes [Ru(η5-C9H7){κ3(P,C,C)- Ph2P(CH2CR=CH2)}(PPh3)][PF 6] (R = H, Me)
Alvarez, Patricia,Lastra, Elena,Gimeno, Jose,Brana, Pedro,Sordo, Jose A.,Gomez, Julio,Falvello, Larry R.,Bassetti, Mauro
, p. 2956 - 2966 (2008/10/09)
The stereoselective synthesis and reactivity of the mixed-phosphine complexes [Ru(η 5-C9H7){k 3(P,C,C)- Ph2P(CH2CR=CH2)}(PPh 3)][PF 6] (R=H, Me) bearing the hybrid hemilabile ligand allyldiphenylphosphine were discussed. It was found that the reaction of R=H with sodium methoxide in methanol yielded the hybride derivative complexes. The olefin exchange occurred with regard to parallel first-order and second-order pathways. The ruthenium fragment acting as a Lewis acid with chiral recognition provides an appropriate means to envisage potential enantioselective transformations of prochiral olefins.
