Ph 3 P/DDQ/NH 4 SCN as a New and Neutral System for Direct Preparation of Diethyl α-Thiocyanatophosphonates from Diethyl α-Hydroxyphosphonates (original) (raw)

Synthesis of Phosphonate Derivatives and Phosphonate Peptide Analogues

1996

A general method for the preparation o f a wide variety o f phosphonate derivatives, including phosphonamides, thiophospbonamides, thiophosphonates, and dithiophosphonates, from reduced phosphorus intermediates has been developed. Esters (or thioesters) o f tf-phosphinates are converted to the highly reactive phosphonochloridites by non-oxidative activation with dichlorotriphenylphosphorane. The phosphonochloridites react readily with alcohols, amines and thiols and after in situ oxidation or sulfurization, phosphonate derivatives can be isolated in moderate to very good yields (47-85%). This method was used to synthesize a thiophosphonate dipeptide, Boc-Val-i/f[P(S)(OBu)0 ]Ala-C>CH3 (15b), two thiophosphonam ide dipeptides, Boc-Val-i/4 P(S)(OrBu)NH]Gly-OCH2CH3 (1 6 b) and Fm oc-A ibi/4P(S)(OBn)NH]Gly-OCH2CH3 (20), and two phosphonate dipeptides, Fmoc-Aibi^[P(0)(0Bn)NH]Gly-0CH2CH3 (1 9 ) and Fmoc-Phe-V'tP(S)(OBn)NH]GlyOCH2CH3 (21). Compounds 15b , 16b and 20 represent the fir...

To date the greenest method for the preparation of α-hydroxyphosphonates from substituted benzaldehydes and dialkyl phosphites

Green Processing and Synthesis, 2017

Recent synthetic methods for α-hydroxyphosphonates comprise a green, solvent-free accomplishment of the Pudovik reaction that was typically followed by extractions and recrystallization, or even by chromatography, or other operations. We now developed a general procedure applying 10% of triethylamine as the catalyst and a minimum quantity of acetone as the solvent, giving the products in a pure form after a reflux of 5–120 min following the addition of some n-pentane and crystallization on cooling.

Synthesis and Reactions of α-Hydroxyphosphonates

Molecules, 2018

This review summarizes the main synthetic routes towards α-hydroxyphosphonates that are known as enzyme inhibitors, herbicides and antioxidants, moreover, a number of representatives express antibacterial or antifungal effect. Special attention is devoted to green chemical aspects. α-Hydroxyphosphonates are also versatile intermediates for other valuable derivatives. O-Alkylation and O-acylation are typical reactions to afford α-alkoxy-, or α-acyloxyphosphonates, respectively. The oxidation of hydroxyphosphonates leads to ketophosphonates. The hydroxy function at the α carbon atom of hydroxyphosphonates may be replaced by a halogen atom. α-Aminophosphonates formed in the nucleophilic substitution reaction of α-hydroxyphosphonates with primary or secondary amines are also potentially bioactive compounds. Another typical reaction is the base-catalyzed rearrangement of α-hydroxy-phosphonates to phosphates. Hydrolysis of the ester function of hydroxyphosphonates leads to the corresponding phosphonic acids.

Synthesis of phosphonates from .alpha.-hydroxy carbonyl compounds and dialkyl phosphorochloridites

The Journal of Organic Chemistry, 1989

methylene chloride). After concentration of the solvent, 3 was crystallized from diethyl ether/hexane (80 mg, 57%): HPLC, column A (A/B, 25:75), tR = 5.96 min (coelution with the natural nordidemnin B); HRFABMS, m/e (M' + H) 1098.61 (C&&@,, requires 1098.63); CD (methanol) [~l z l s +212, [el2, +145, [elm5-72 (natural nordidemnin B, [6']219 +221, [e1234 +153 [el,-67.

Synthesis of diethyl 2-thioxo-1,2,3,4-tetrahydroand hexahydropyrimidine-5-phosphonates

Mendeleev Communications, 2008

The reaction of sodium enolate of diethyl (2-oxoprop-1-yl)phosphonate with N-(1-tosylprop-1-yl)thiourea results in the stereoselective formation of diethyl (4R*,5R*,6R*)-6-ethyl-4-hydroxy-4-methyl-2-thioxohexahydropyrimidine-5-phosphonate, which is transformed into diethyl 4-ethyl-6-methyl-2-thioxo-1,2,3,4-tetrahydropyrimidine-5-phosphonate and diethyl (4R*,5S*,6R*)-4-ethyl-6-methyl-2-thioxohexahydropyrimidine-5-phosphonate by acid-catalysed dehydration and stereoselective reduction with NaBH 4-CF 3 COOH, respectively.

Thioureidoalkylphosphonates in the synthesis of 1-aminoalkylphosphonic acids. The Ptc-aminophosphonate method

Arkivoc, 2011

1-Aminoalkylphosphonic acids (AA P) as structural analogues of protein amino acids (AA C), are important inhibitors of amino acids metabolism. One of the three methods which have contributed to the development of the chemistry of 1-aminoalkylphosphonic acids is the Ptcaminoalkylphosphonate (Phenylthiocarbamoylaminoalkylphosphonate) method which allows a time saving synthesis of structurally diverse AA P of analytical purity on mmol-mol scale This review presents a comprehensive survey of this methodology development, with an emphasis on its scope and limitations.