Three-component reactions of amines, triethylorthoformate and diethyl phosphite are efficiently catalyzed by ytterbium perfiuorooctanoate [Yb(PFO)(3)] in 1-butyl-3-methylimidazolium chloride ([bmim][Cl]) ionic liquid, giving the corresponding aminomethylene bisphosphonates in good yields. The catalyst can be recovered and reused for several times without any significant loss of activity. (C) 2011 Elsevier B.V. All rights reserved.
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作者:V. I. Krutikov、A. V. Erkin、P. A. Pautov、M. M. Zolotukhina
DOI:10.1023/a:1024775501781
日期:——
A series of substituted aminomethylenebisphosphonates is prepared by reaction of dialkyl hydrogen phosphites with triethyl orthoformate and corresponding heteryl- or arylamine. The determining factor in the formation of the target products is appearance of an intermediate associate between the ortho ester and amine. The rate and selectivity of the process can be increased by using a nonpolar solvent to stabilize the transition state of the reaction. Crown ether catalysis increases the selectivity of the process by 10-20%. The synthesized aminomethylenebisphosphonates whose structure was established by NMR spectroscopy exhibit a moderate antibacterial and anticholinesterase activity.
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