Synthesis and Reactions of α-Hydroxyphosphonates

Abstract

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.

Efficient synthesis of dipeptide analogues of α-fluorinated β-aminophosphonates

“…Unfortunately, we were not able to isolate the pure anti-isomer in every case. The latest research shows that this reaction can successfully be carried out under milder conditions, without any solvent and in the presence of a weak base [33]. After testing many modifications, it turned out that the use of triethylamine (1 equiv) as a base, and without a solvent, gave the best results with alde- hydes 4 (1 equiv) and diethyl phosphite (1 equiv).…”

Synthesis ofα‐Hydroxyphosphonates Containing Functionalized 1,2,3‐Triazoles

“…Aiming to determine the best reaction conditions for the reaction, 2‐(4‐phenyl‐1 H ‐1,2,3‐triazol‐1‐yl)benzaldehyde ( 1 a ) and diethyl phosphite ( 2 a ) were chosen as the standard starting materials. Initially, the used reaction conditions were adapted from previous reports, [75–77] in which a solvent‐free mixture of triazole 1 a (0.25 mmol) reacted with 3.0 equiv. of diethyl phosphite ( 2 a ) reacted at 70 °C in an open vessel system.…”

Synthetic Strategies, Reactivity and Applications of 1,5-Naphthyridines

“…Aminophosphonates and their corresponding aminophosphonic acids are known as amino acid mimetics and, therefore, affect the physiological activity of the cell [ 56 , 57 ]. The synthesis of 3-phosphonylated aminophosphonates from α , β-unsaturated imines through tandem 1,4-1,2-phosphite addition was first accomplished by the use of both silylated dialkyl phosphite and trialkyl phosphates [ 58 ].…”