Hydrolysis of Cyclic Phosphites/Phosphoramidites and Its Inhibition-Reversible Cyclization of Acyclic Phosphonate Salts to Cyclic Phosphites

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• 作者：N. Satish Kumar ; Sudha Kumaraswamy ; Musa A. Said ; and K. C. Kumara Swamy
• 刊名：Organic Process Research & Development
• 出版年：2003
• 出版时间：November 2003
• 年：2003
• 卷：7
• 期：6
• 页码：925 - 928
• 全文大小：74K
• 年卷期：v.7,no.6(November 2003)
• ISSN：1520-586X

文摘

Hydrolysis of cyclic phosphites/phosphoramidites (OCH₂CRR'CH₂O)PX [X = OPh (1), NMe₂ (2)] in the presence ofintentionally added water is effectively inhibited by using simpleadditives such as KF, K₂CO₃, Et₃N, and molecular sieves.Among these, K₂CO₃ gave the best results. Cyclic H-phosphonates (OCH₂CRR'CH₂O)P(O)H (3), which are the tautomericforms of the phosphites (OCH₂CRR'CH₂O)P(OH), undergofacile hydrolysis in the presence of aqueous amines to give theacyclic phosphonate salts [H₂NMe₂]⁺[(HOCH₂CRR'CH₂O)P(O)(H)(O^-)] (4) that can be reverted back to 3 upon simple heating.Interestingly, competitive reactions of (OCH₂CRR'CH₂O)PX[X = Cl (I-III), NMe₂ (2)] with phenol and water in thepresence of K₂CO₃ led only to the phenoxy derivatives and notto the hydrolysis products.