Diastereoselective synthesis of Pro-Phe phosphinyl dipeptide isosteres

Potential chemical transformation of phosphinic acid derivatives and their applications in the synthesis of drugs

The chemical transformation of phosphinic acid is a well-considered mature area of research on account of the historical significant reactions such as Kabachnik-Fields, Mannich, Arbuzov, Michaelis-Becker, etc. Considerable advances have been made over last years especially in metal-catalyzed, free-radical processes and asymmetric synthesis using catalytic enantioselective. As a result, the aim of this synopsis is to make the reader familiar with advances in the approaches of phosphinic acids toward the synthesis of highly functionalized and valuable buildings blocks. Another purpose of this survey is to provide the current status of the applications of phosphinic acids in the synthesis of drugs.

On the cost of academic methodologies

Synthetic methodologies can be easily compared using the Cost of Academic Methodologies (CAM) parameter, which estimates the cost of making a mole of a product.

Stereoselective Synthesis of α-Amino-C-phosphinic Acids and Derivatives

α-Amino-C-phosphinic acids and derivatives are an important group of compounds of synthetic and medicinal interest and particular attention has been dedicated to their stereoselective synthesis in recent years. Among these, phosphinic pseudopeptides have acquired pharmacological importance in influencing physiologic and pathologic processes, primarily acting as inhibitors for proteolytic enzymes where molecular stereochemistry has proven to be critical. This review summarizes the latest developments in the asymmetric synthesis of acyclic and phosphacyclic α-amino-C-phosphinic acids and derivatives, following in the first case an order according to the strategy used, whereas for cyclic compounds the nitrogen embedding in the heterocyclic core is considered. In addition selected examples of pharmacological implications of title compounds are also disclosed.

[Stereocontrolled synthesis of phosphinyl dipeptide isosteres using an asymmetric center at the phosphorus atom]

Phosphinyl dipeptide isosteres (PDIs) are important compounds for the development of potent and selective inhibitors of various aspartic proteases and Zn metalloproteases. The stereochemistry of PDIs affects their biological activity. PDIs were prepared successfully using the concept of asymmetric induction from the chiral phosphorus atom of the phosphinate moiety to the neighboring carbon atom. This methodology involves diastereoselective α-alkylation and β'-alkylation of P-chiral phosphinate derivatives, prepared through lipase-catalyzed kinetic resolution, which produces Phe-Ala type and Pro-Phe type PDIs. The synthesis of Leu-Pro type PDIs in a protected form was achieved through a cross-coupling reaction of stereodefined α-amino-H-phosphinate with alkenyl triflate, followed by diastereoselective hydrogenation of the alkene moiety.