Aminophosphine oxides in a pyridine series. Studies on the cleavage of pyridine-2- and pyridine-4-yl-(N-benzylamino)-methyldiphenylphosphine oxides in acidic solutions

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• 作者：Waldemar Goldeman ; Tomasz K. Olszewski ; Bogdan Boduszek and Wanda Sawka-Dobrowolska
• 关键词：Aminophosphine oxides ; Pyridine ; Acidic solutions
• 刊名：Tetrahedron
• 出版年：2006
• 出版时间：1 May 2006
• 年：2006
• 卷：62
• 期：18
• 页码：4506-4518
• 全文大小：660 K

文摘

The synthesis and reactions of 1-(N-benzylamino)-1-(2-pyridyl)- and 1-(N-benzylamino)-1-(4-pyridyl)-methyldiphenylphosphine oxides are described. It was found that these compounds were exceptionally easy to cleave in aqueous sulfuric acid solutions to form diphenylphosphinic acid and the corresponding N-(pyridylmethyl)-benzylamines. The structure of a single diastereoisomer, that is, the (R)-(+)-1-[N-(α-methylbenzylamino)]-1-(4-pyridyl)-(S)-methyldiphenylphosphine oxide was determined by X-ray crystallography. The acidic alcoholysis of the selected model chiral pyridine aminophosphine oxides was investigated by means of ³¹P NMR spectroscopy. The cleavage kinetics were also studied. On the basis of the obtained results, a mechanism of the cleavage was formulated.