22572-29-8Relevant academic research and scientific papers
Di-ruthenium complexes having diphosphines and carbonyls: Formation, structure, and catalytic hydrogenation of alkynes
Mukherjee, Aparajita,Paul, Piyali,Bhattacharya, Samaresh
, p. 47 - 57 (2017/02/26)
Reaction of three selected diphos ligands, viz. 1,2-bis(diphenylphosphino)ethane (L1), 1,3-bis(diphenylphosphino)propane (L2) and 1,4-bis(diphenylphosphino)butane (L3), with [{Ru(CO)2Cl2}n] has afforded di-ruthenium complexes of type [Ru2(L)3(CO)2Cl4], (1–3). Crystal structure of complex 1 has been determined, and molecular structures of complexes 2 and 3 have been optimized through DFT method. Formation of the unexpected di-ruthenium complexes has been probed through DFT calculations. In dichloromethane solution all the complexes show intense absorptions in the visible and ultraviolet regions. Cyclic voltammetry on the complexes shows an irreversible oxidation within 0.79–1.53 V vs SCE, and an irreversible reduction within ?1.20 to ?1.33 V vs SCE. The di-ruthenium complexes efficiently catalyze hydrogenation of alkynes to the corresponding alkenes.
Zirconocene-mediated and/or catalyzed unprecedented coupling reactions of alkoxymethyl-substituted styrene derivatives
Ikeuchi, Yutaka,Taguchi, Takeo,Hanzawa, Yuji
, p. 4354 - 4359 (2007/10/03)
Reactions of o-(alkoxymethyl)styrene derivatives with a stoichiometric amount of zirconocenebutene complex (zirconocene equivalent, "Cp 2Zr") brought about an insertion of the zirconocene species into a benzylic carbon-oxygen bond. The oxidative insertion of Cp2Zr to the benzylic carbon-oxygen bond is a result of sequential reactions: (i) formation of zirconacyclopropane by the ligand exchange with o-(alkoxymethyl)styrene, (ii) elimination of the alkoxy group through an aromatic conjugate system giving metalated o-quinodimethane species, and (iii) transfer of zirconium metal to the benzylic position. Through use of a catalytic amount of "Cp2Zr", however, unprecedented homo-coupling reactions (dimerization) of o-(alkoxymethyl)styrene derivatives occurred to give a tetracyclic compound. On the other hand, reactions of o-(1-alkoxyisopropyl) styrene derivatives gave rise to the analogous tetracyclic compounds regardless of the amount of "Cp2Zr" (stoichiometric or catalytic). Heterocoupling product between o-(1-alkoxyisopropyl)styrene and styrene congeners was obtained in high cis stereo- and regioselectivity by treating o-(1-alkoxyisopropyl)styrene derivatives with "Cp2Zr" in the presence of an excess amount of styrene derivatives.
Highly active palladium catalysts supported by bulky proazaphosphatrane ligands for stille cross-coupling: Coupling of aryl and vinyl chlorides, room temperature coupling of aryl bromides, coupling of aryl triflates, and synthesis of sterically hindered biaryls
Su, Weiping,Urgaonkar, Sameer,McLaughlin, Patrick A.,Verkade, John G.
, p. 16433 - 16439 (2007/10/03)
A family of proazaphosphatrane ligands [P(RNCH2CH 2)2N(R′NCH2CH2): R = R′ = i-Bu, 1; R = Bz, R′ = 1-Bu, 3; R = R′ = Bz, 4] for palladium-catalyzed Stille reactions of aryl chlorides is described. Catalysts derived from ligands 1 and 4 efficiently catalyze the coupling of electronically diverse aryl chlorides with an array of organotin reagents. The catalyst system based on the ligand 3 is active for the synthesis of sterically hindered biaryls (di-, tri-, and tetra-ortho substituted). The use of ligand 4 allows room-temperature coupling of aryl bromides and it also permits aryl inflates and vinyl chlorides to participate in Stille coupling.
