654066-05-4Relevant academic research and scientific papers
Reactions of the cationic fragments [RuCp(PPh2NHR) 2]+ and [RuTp(PPh2NHR)2]+ (R = Ph, re-Pr) with Alkynes: Formation of four-membered azaphosphacarbenes
Pavlik, Sonja,Mereiter, Kurt,Puchberger, Michael,Kirchner, Karl
, p. 3561 - 3575 (2008/10/09)
The synthesis of RuCp(PPh2NHR)2Cl (1a,b; R = Ph, n-Pr) and RuTp(PPh2NHR)2Cl (2a,b) is reported. Chloride abstraction from 1a with AgCF3SO3 affords RuCp(PPh 2NHPh)2(η1-OSO2CF3) (3), whereas when AgSbF6 is used instead [RuCp(κ2(P, P)-PPh2NHC6H4PPh2)(NH 2-Ph)]+ (4) is formed. In the course of this reaction the P-N bond of one PPh2NHPh ligand is cleaved while a new P-C bond is formed, with concomitant formation of an aniline ligand. In the presence of Ag+ (CF3SO3- or SbF6 -) complexes 1 and 2 react with terminal alkynes HC≡CR′ (R′ = Ph,p-C6H4Me, n-Bu) and propargylic alcohols to give novel azaphosphacarbene complexes of the types [RuCp(κ 2(C,P)=C(CH2R′)N(R)PPh2) (κ1(P)-PPh2NHR)]+ (5a-c, 6a-c), [RuTp(κ2(C,P)=C(CH2R′)N(R)PPh 2)(κ1(P)-PPh2NHR)]+ (14a,b, 15a-c), [RuCp(κ2(C,P)= C(CH=CPh2)N(Pr n)PPh2)(κ1(P)-PPh2NHPr n)]+ (12), and [RuTp(κ2(C,P)=C(CH=CPh 2)N(Prn)-PPh2)(κ1(P)-PPh 2NHPrn)]+ (17). These reactions proceed via vinylidene and allenylidene intermediates, respectively, which could be isolated in some cases: viz. [CpRu(PPh2NHPh)2-(=C=C=CPh 2)]+ (11) and [RuTp(PPh2NHR) 2(=C=C=CPh2)]+ (16a,b). Furthermore, complexes 1a,b react with 3-butyn-1-ol to yield the oxacyclopentylidene complexes [CpRu(PPh2-NHR)2(=C4H6O)] + (7a,b). In sharp contrast to 6a-c (R = n-Bu), 5a-c (R = Ph) turned out to be quite sensitive toward traces of water, leading eventually to the formation of the aminocarbene complexes [RuCp(=C(CH2R)NHPh)(PPh 2NHPh)(κ1(P)-PPh2OH)]+ (8a,b) featuring a κ1(P)-coordinated PPh2OH ligand. This ligand could be easily deprotonated to yield the neutral complex RuCp(=C(CH 2Ph)NHR)(PPh2NHPh)(κ1(P)-OPPh 2) (10a,b). The formation of these complexes is reversible. Finally, representative structures have been determined by X-ray crystallography.
Half-sandwich ruthenium(II) complexes of aminophosphines: Synthesis, structures and catalytic applications in C-C coupling reactions between styrenes and diphenyldiazomethane
Priya, Srinivasan,Balakrishna, Maravanji S.,Mobin, Shaikh M.,McDonald, Robert
, p. 227 - 235 (2007/10/03)
The half-sandwich Ru(II) complexes of the type [CpRu(PPh2 N(H)R)(PPh3)Cl], [CpRu(PPh2N(H)R)2Cl] (R=Ph, C6H11) and [CpRu(PPh2N(R′) PPh2-κP,κP)(PPh3)]Cl (R′=Et, nPr, iPr, nBu), were synthesized and the structures of complexes [CpRu(PPh2N(H)Ph)(PPh3) Cl] and [CpRu(PPh2N(H)Ph)2Cl] were confirmed by single crystal X-ray diffraction studies. All ruthenium complexes were employed in the cyclopropanation reaction of styrene derivatives in the presence of diphenyldiazomethane. All complexes afford 1,1,3,3-tetraphenyl cyclobutane along with cyclopropane derivatives; complex, [CpRu(PPh2N(nBu)PPh2-κ P,κP) (PPh3)]Cl shows better selectivity in the formation of 1,1,2-triphenylcyclopropane. In all reactions appreciable amounts of cyclopropanation products and metathesis products, 1,2-diphenylcyclopropane and 1,1-diphenylethene were obtained along with 1,1,3-triphenylpropene derivatives. The variable temperature NMR studies have suggested that the cyclopropanation reactions in the presence of ionic complex, [CpRu(PPh2N(R′)PPh 2-κP,κP)(PPh3)]Cl proceeds via carbene intermediate, [CpRu(=CPh2)(PPh2N(R′) PPh2-κP)(PPh3)]Cl.
