Organocatalytic Cyclization of COS and Propargylic Derivatives to Value‐Added Heterocyclic Compounds

Abstract

The organocatalytic cyclization of propargylic amines/amides with carbonyl sulfide (COS) was firstly achieved by employing COS adducts of Lewis base (LB) as organocatalysts, affording various functionalized 1,3‐thiazolidine‐2‐ones, and 1,3‐thiazolidine‐2,4‐diones derivatives in a highly chemo‐ and stereoselective manner. The isotope labeling and stoichiometric experiments suggested the LB‐COS adducts preferentially mediated basic ionic pair mechanism. Furthermore, the practical application of this methodology was highlighted by the highly efficient synthesis of rosiglitazone using COS as sulfur source.

Unexplored Vinylic-Substituted 5-Benzylidenethiazolidine-2,4-diones: Synthesis and DFT/NMR Stereochemical Assignment

“…To access new bioactive molecules, several modifications to this structure could be envisaged. N -alkylations of the TZD core and variations of the aryl moiety of BTZD represent the easiest and most explored methods. − On the other hand, vinylic functionalization has rarely been described, which is surprising considering the density of the literature dealing with this structure. ,− Moreover, the very few reported vinylic modulations of the BTZD moiety resulted from Knoevenagel condensation involving aryl ketones (instead of aldehydes) and a thiazolidine-2,4-dione 2a (TZD, Scheme , path a). This methodology has two main drawbacks.…”

Explorations into the sustainable synthesis of cyclic and polymeric carbonates and thiocarbonates from eugenol-derived monomers and their reactions with CO2, COS, or CS2

“…52,53 Although production of cyclic carbonates through catalytic coupling of different epoxides with CO 2 is well established in the literature, [54][55][56][57][58][59][60][61][62][63] the corresponding cycloaddition products with COS are less explored. 64,65 These cyclic carbonates or monothiocarbonates are an important class of compounds due to their usage as intermediates in different chemical transformations, 66 as electrolytes in lithium ion batteries, 67 and in some instances for making linear polymers via ROP. 13,68 Thus production of these cyclic compounds in a sustainable manner will be pivotal to further enhance the exploration of their applications.…”

Simultaneous Immobilization of CO2 and H2S by Propargyl Amines under Mild Conditions: Efficient Synthesis of Thiazolidine-2-ones

“…For example, they act as protective groups of ibuprofen prodrugs or as an intermediate in the preparation of fosthiazate insecticides. − Conventionally, thiazolidine-2-ones are prepared by the cyclization strategy of 2-aminoethane-1-thiols with phosgene, urea, or 1,1-carbonyldiimidazoles, but the substrate scope is limited (Scheme a). Furthermore, the cyclization reaction of propargylic amines with carbonyl sulfide or the precursors of carbonyl sulfide (S 8 and TFBen) has also been explored to afford thiazolidine-2-ones, but expensive and elaborate catalysts or reactants are required (Scheme b). Therefore, a novel yet efficient synthetic method needs to be developed to construct thiazolidine-2-one motifs.…”