861656-44-2Relevant 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.
