Experimental and Computational Studies on the 1,3‐Dipolar Cycloaddition between Enantiomerically Pure 2,3‐Dihydrothiazoles and Nitrones

Abstract

The diastereoselective 1,3‐dipolar cycloaddition between nitrones and enantiomerically pure 2,3‐dihydrothiazoles derived from L‐cysteine, with different oxidation states at the sulfur atom has been studied experimentally and computationally. The reaction takes place with complete regioselectivity and diastereofacial selectivity. On the other hand, the exo/endo selectivity showed a clear dependence of the oxidation state at the sulfur atom. The computational calculations agree with the experimental findings.

The Crucial Role of S‐oxidation State on the Selectivity and Reaction Rate of the 1,3‐Dipolar Cycloaddition of Azomethine Ylides and Homochiral Thiazolines

“…In the last years, we have reported cycloaddition reactions between diazoalkanes [35] , nitrones, [36] or several dienes [37] and homochiral thiazolines (1) to obtain modified cysteines and masked modified cysteines with excellent results (Scheme 1). Therefore, we envisioned the high potential of these peculiar thiazolines (1) scaffolds as dipolarophiles in the cycloaddition with azomethine ylides, generated in situ from α-imino esters.…”

Density Functional Theory Study of Substituent Effects on the 1,3-Dipolar Cycloaddition Mechanism

“…Introduction 1,3-Dipolar cycloaddition is a reaction that not only plays an important role in the synthesis of five-membered heterocyclic compounds, but also has great significance in theoretical organic chemistry. [1][2][3][4] Diversity-oriented synthesis refers to a kind of forward synthesis that usually uses branching diffusion to focus on the diversity and complexity of compounds with the aim of expanding the compound library from point to face. [5][6][7] Because this synthetic method can use combinatorial chemistry to synthesize similar compounds, the properties and structure-activity relationship of the synthesized compounds can be easily studied.…”