Element-Substituted Acylphosphines

Abstract

Element-substituted acylphosphines are stable in form 2 R¹P(ER_n)COR² (A), when E=Ge, Sn, Sb, P, T1 and in form R¹ P=C(OER_n)R² by NMR data. The reaction     

Stability analysis of closed-path tape transports

Institute of Mechanical Engineering, St. Petersburg. Translated from Prikladnaya Mekhanika, Vol. 28, No. 2, pp. 67–74, February, 1992.     

An unusual rearrangement during pyridine synthesis. Anomalous condensation of a β-keto enamine with a tetronic acid.

The condensation of β-keto enamine 1 with 5-methyltetronic acid takes an anomalous course. Single crystal X-ray analysis and chemical evidence establish the rearranged pyridine structure 15 for this condensation product.     

Reversible Phosphaalkene Formation Frol'i Iminodi-Phosphines

Abstract

Addition of variousnucleophiles to phosphaalkenes is considered to be irreversible. As an example, the quantitative formation of iminodiphosphine III from phosphinous amide and phosphaalkene was recently reported (1).     

Synthesis of asymmetric secondary phosphines by the cross coupling of arylhalides with silylphosphines

The cross coupling of aryl halides with alkyl(trimethylsilyl)phosphines catalyzed by zero-valent palladium complexes yields secondary alkylarylphosphoranes containing both electron-donor and electron-withdrawing substituents in the aromatic ring. The reversible disproportionation of alkylsilylphosphines to give AlkPH₂ and AlkP(SiMe₃)₂ was observed for the first time during this reaction. This disproportionation does not affect the yield of AlkArPH, which are formed in virtually quantitative yield, due to the high rate of cross coupling with AlkP(SiMe₃)H₂ and the reversibility of the disproportionation process.M. V. Lomonosov Moscow State University, 119899 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 7, pp. 1645–1648, July, 1992.     

Dysprosium(III) catalysis in organic synthesis

1. Download : Download full-size image