P-aminophosphonates

Addition of the lithium anion of chloromethylphosphonate to sulfinimine 126 gave a-chloro-P-aminophosphonates 195 in a ratio of 59 41 and 98% total yield.104 The diastereomeric products can be separated and each converted to the corresponding aziridine-2-phosphonates 196, new building chiral blocks for the enantioselective synthesis of a-aminophosphonates 197 and azirinyl phosphonates 198.104... 

Phosphonylated. V-bciizyI enamine, formed from benzylamine and diethyl 2-oxopropylphosphonate, undergoes aza-annulation with acryloyl chloride in refluxing THF to provide a phosphonylated unsaturated lactam in 72% yield. - Subsequent hydrogenation generates a 78 22 ratio of diastereomeric products in 67% yield (Scheme 7.114). These compounds represent an interesting class of rotationally constrained P-aminophosphonic acid analogues. 

Defacqz, N., Ibuillaux, R., Cordi, A., and Marchand-Brynaert, J., P-Aminophosphonic compounds derived from methyl l-dimethoxy-phosphoryl-2-succinimidocyclohex-3-ene-l -carhoxylates, J. Chem. Soc., Perkin Trans. 1, 2532, 2001. 

Aminohydroxylations. Baylis-Hillman alkenes give predominantly syn-diols, whereas the reaction with a,(3-unsaturated phsophonates gives rise to a-hydroxy-P-aminophosphonates. ... 

Nakamura et al. reported the first highly enantioselective desymmetrisation of aziridines with phosphites catalysed by Cinchona alkaloid amides in combination with Et2Zn (Scheme 15.15). The reaction proceeds in benzene with optimally 10 mol% of both Et2Zn and iV-(2-picolinoyl)-9-amino-9-deoxy-epi-cinchonine 2, affording p-aminophosphonates in up to 90% yield and in up to 99% ee. 

Kafarsky, P. Mastalerz, P. Aminophosphonates, Natural Occurrence, Biochemistry, Biological Properties, Inst. J. Wirkstofforsch. Berlin, 1984, 73. 

Addition of diethyl lithiodifluoromethylphosphonate to enantiomerically pure aromatic, heteroaromatic and aliphatic aldehyde-derived sulfinimines afforded diastereomerically pure N-sulfinyl oc,a-difluoro-P-aminophosphonates (200) which were used to prepare a,a-difluoro-P-aminophosphonic adds (201) and the sodium salt of difluorophosphonamidic acid (7 )-(202) (Scheme 73). ... 

Efficient synthesis of racemic p-aminophosphonates (125) and bis-(diethylphosphorylethyl) substituted amines and diamines (126) via the aza-Michael reaction in water has been described by Matveeva et The products have been obtained in quantitative yields and in high purity over short reaction times. 

SCHEME 4.126 Synthesis of P-aminophosphonates through an Arbuzov process [207, 208]. 

SCHEME 4.127 Preparation of P-aminophosphonates using an acyclic amide protecting group [209]. 

Synthesis of vinylphosphonate esters. Vinylphosphonates are a well-known class of organophosphorus compounds that are very useful intermediates for the construction of many synthetically and pharmaceutically important compounds including acyclic, carbocyclic, and especially heterocyclic compounds, p-aminophosphonates and l,2-epo)yallylphosphonates. ° Terminal vinylphosphonates (1-atyl or 1-allyl... 

Palacios F, Alonso C, de los Santos JM (2005) Synthesis of p-aminophosphonates and-phosphinates. Chem Rev 105 899-932... 

A series of a-mono- and ot,ot-difluoro-p-ketophosphonates (620) were synthesised in moderate to good yields with excellent selectivities via electrophilic fluorination of (618) by Selectfluor (619). The synthetic potential of the obtained ot-monofluoro-p-ketophosphonates (620) was demonstrated by their application in the synthesis of cx-monofluoro-p-aminophosphonates (621), as useful building blocks in preparation of phosphapeptides (Scheme 152). ° ... 

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