Reactions of Ruthenium-Aminophosphane Complexes with Diynes: P-N Bond Activation and Formation of Novel Phosphaallyl, Azaallyl, and Aminocarbene Complexes

• Published in: European Journal of Inorganic Chemistry 2006-03, Vol.2006 (5), p.1006-1021
• Main Authors: Pavlik, Sonja, Jantscher, Florian, Dazinger, Georg, Mereiter, Kurt, Kirchner, Karl
• Format: Article
• Language: English
• Subjects: Azaallyl complexes; Density functional calculations; Phosphaallyl complexes; Ruthenium
• ISSN: 1434-1948; 1099-0682
• DOI: 10.1002/ejic.200500942

The aminophosphane complexes [RuCp(PPh2NRR′2)(CH3CN)2]+ and [RuCp*(PPh2NRR′2)(CH3CN)2]+ (NRR′ = NHnPr, NEt2, NC5H5) react with 1,6‐heptadiyne and 1,7‐octadiyne to yield novel η3‐phosphaallyl–η2‐vinylamine complexes of the types [RuCp{η3‐(P,C,C)‐PPh2CH=C–(CH2)n–η2‐(C,C)–C=CHNRR′2}]+ and [RuCp*{η3‐(P,C,C)‐PPh2CH=C–(CH2)n–η2‐(C,C)‐C=CHNRR′2}]+ (n = 3, 4). These complexes are the kinetic products but eventually form the η1‐phosphaallyl–η3‐azaallyl complexes [RuCp{η1‐(P)‐PPh2CH=C–(CH2)n–η3‐(C,C,N)‐CCHNRR′2}]+ and [RuCp*{η1‐(P)‐PPh2CH=C–(CH2)n–η3‐(C,C,N)‐CCHNRR′2}]+, respectively. With n = 3 elevated temperatures are required, while with n = 4 this conversion takes places already at room temperature. The only exception is [RuCp*(PPh2NHnPr)(CH3CN)2]+ where amido butadiene complexes [RuCp*{η1‐(N)‐NnPrPPh2‐η4‐CH=C(CH2)nCH=CH2}]PF6 (n = 3, 4) are obtained instead. In the case of [RuCp{η1‐(P)‐PPh2CH=C–(CH2)3–η3‐(C,C,N)‐CCHNRR′2}]+ with NRR′ = NEt2 and NC5H5, a further rearrangement took place at elevated temperatures affording the aminocarbenes [RuCp{=C(NRR′)‐η2‐(C,C)‐C(CH2)3C–CH2–(η1‐(P)‐PPh2)}]+. Representative X‐ray structures are presented. Moreover, conceivable mechanisms for all these reaction sequences are established by means of DFT/B3LYP calculations. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)