Transannular rearrangement of activated 2,5-diketopiperazines: a key route to original scaffolds

An efficient and original stereocontrolled transannular rearrangement starting from activated 2,5-diketopiperazines has been developed, an opportunity for the medicinal chemistry field, which requests access to novel biological scaffolds. This powerful ring contraction, which can be related to a stereoselective aza-version of the Chan rearrangement, allows for example the one-step synthesis of various tetramic acids, access to 2-disubstituted statins, or the synthesis of relevant lactam-constrained dipeptide mimetics using a TRAL-RCM sequence.     

Efficient solid-phase synthesis of sulfahydantoins

A novel solid-phase strategy allows the efficient preparation of "traceless" sulfahydantoins. A total of 28 derivatives, with crude purity generally higher than 85%, were prepared by parallel synthesis. Through reductive alkylations, Mitsunobu reactions, and sulfamoylation reactions on oxime resin, the synthetic strategy affords sulfahydantoin derivatives selectively substituted at N(2), N(5) and N(2), N(5) positions, although yields of disubstituted compounds are lower. The mild reaction conditions involved lead to sulfahydantoins without racemization.     

Simple and efficient synthesis of new chiral N,N′‐sulfonyl bis‐oxazolidin‐2‐ones

A series of new chiral N,N′‐sulfonyl bis‐oxazolidin‐2‐ones were synthesized starting from 2‐aminoalcohols, sulfuryl chloride, and diethyl carbonate. This method utilizes natural amino acids as a source of chirality for the preparation of oxazolidinones. © 2006 Wiley Periodicals, Inc. Heteroatom Chem 17:61–65, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20183     

Synthèse Et Cyclisation De Carboxylsulfamides Dérivés D'amines Et D'α-Hydroxyesters. Éavaluation De L'Activité Bactéeriostatique

Abstract

Les carboxylsulfamides sont obtenus à partir de l'isocyanate de chlorosulfonyle, d'amines primaires et d'α-hydroxyesters. Après réduction alcaline, ces carboxylsulfamides sont cyclisés dans les conditions de la réaction de Mitsunobu pour conduire aux N-sulfamoyloxazolidinones chides avec des rendements élevés.

The synthesis of carboxylsulfamides was carried out starting from chlorosulfonyl isocyanate, primary amines and α-hydroxyesters. After reduction, the carboxylsulfamides were cyclised under Mitsunobu conditions giving N-sulfamoyloxazolidinones in good yields.     

Synthese et N-Acylation Regiospecifique de 1,2,5-Thiadiazolidines 1,1-Dioxydes Chirales

The regiospecific synthesis of chiral N-acyl cyclosulfamides (sulfa-analogues of cyclic ureas) was carried out starting from chlorosulfonyl isocyanate (CSI), 1-substituted N-benzyl-2-chloroethylamine hydrochloride and acyl chloride. Chiral N-acyl-thiadiazolidines 1,1-dioxides have been prepared in high yield starting from the corresponding cyclosulfamides acyl chloride, triethylamine and a catalytic amount of 4-(N,N-dimethylamino)pyridine. L'accès régiospécifique aux cyclosulfamides chiraux N-acylés (analogues sulfonés d'urèes cycliques) a été développé à partir de l'isocyanate de chlorosulfonyle, de N-benzyl-2-chloroéthylamine chirale substituée en position 1 et de chlorure d'acide. Les N-acyl thiadiazolidines 1,1-dioxydes chirales ont été préparées avec des rendements élevés à partir du cyclosulfamide correspondant par traitement avec un chlorure d'acide en présence de triéthylamine et une quantité catalytique de 4-(N,N-dimethylamino)pyridine.