62993-85-5

Upstream product

• 3581-91-7 4,5-Dimethylthiazole 
• 74-88-4 methyl iodide 

Downstream Products

• 21364-38-5 3,4,5-Trimethyl-Δ⁴-thiazolinthion-(2) 

Relevant academic research and scientific papers

Interface Engineering by Thiazolium Iodide Passivation Towards Reduced Thermal Diffusion and Performance Improvement in Perovskite Solar Cells

Interface engineering has become one of the most facile and effective approaches to improve solar cells performance and its long-term stability and to retard unwanted side reactions. Three passivating agents are developed which can functionalize the surface and induce hydrophobicity, by employing substituted thiazolium iodide (TMI) for perovskite solar cells fabrication. The role of TMI interfacial layers in microstructure and electro-optical properties is assessed for structural as well as transient absorption measurements. TMI treatment resulted in VOC and fill factor enhancement by reducing possible recombination paths at the perovskite/hole selective interface and by reducing the shallow as well as deep traps. These in turn allow to achieve higher performance as compared to the pristine surface. Additionally, the TMI passivated perovskite layer considerably reduces CH3NH3 + thermal diffusion and degradation induced by humidity. The un-encapsulated perovskite solar cells employing TMI exhibit a remarkable stability under moisture levels (≈50% RH), retaining ≈95% of the initial photon current efficiency after 800 h of fabrication, paving the way towards a potential scalable endeavor.

Intercepted dehomologation of aldoses by N-heterocyclic carbene catalysis-a novel transformation in carbohydrate chemistry

The development of an N-heterocyclic carbene (NHC) catalysed intercepted dehomologation of aldoses is reported. The unique selectivity of NHCs for aldehydes is exploited in the complex context of reducing sugars. Examples of strong substrate governance for either intercepted dehomologation or a subsequent redox-lactonisation were identified and mechanistically understood. More importantly, it was shown that catalyst design allowed the tuning of the selectivity of the reaction with structurally unbiased starting materials towards either of the two scenarios.

Robust Organocatalysts for the Cleavage of Vegetable Oil Derivatives to Aldehydes through Retrobenzoin Condensation

A series of thiazolium salts was prepared and tested for the cleavage of the α-hydroxyketone derived from methyl oleate. The robustness of these precatalysts was determined by dynamic thermogravimetric analyses (TGA). It has been shown that the stability of these species is mainly governed by the nature of the counter-anion and some of them were found to be stable until 350–400 °C. The α-hydroxyketone derived from methyl oleate was cleaved under reactive distillation conditions using optimized, thermally robust N-butylthiazolium triflate to give the cleavage product, namely, nonanal and methyl azelaaldehydate, with 85 and 70 % yields. A range of α-hydroxyketones derived from several fatty acids was cleaved to give the corresponding bio-based aldehydes with up to 98 % isolated yields. Finally, this protocol was successfully applied to a high-oleic sunflower oil derivative.

Synthesis and Characterization of Thiazepine/Benzothiazepine Derivatives Through Intramolecular C-2 Ring Expansion Pathway

A facile and highly efficient one-pot synthesis of novel thiazepine and benzothiazepine derivatives was established by ring expansion. With a greener methodology (ultrasonication), a polysubstituted ring system with the thiazepine core moiety can be easily synthesized from simple and easily available reactants in good yields. Moreover, the synthesized compounds show fluorescence and also antioxidant activity.

A simple route to phosphamethine cyanines from S,N-heterocyclic carbenes

Although salts of thiazolium cations are known, many readily prepared iodide salts have eluded spectroscopic and structural characterization; herein, data for a variety of such salts are reported. It has been demonstrated that thiazolium cations can be deprotonated to generate S,N-heterocyclic carbenes and their "electron rich olefin" dimers, but use of the former has been largely overshadowed by that of the more common N-heterocyclic carbenes. We report herein that the deprotonation of thiazolium iodides and their subsequent reaction with a conveniently prepared triphosphenium precursor grants phosphamethine cyanine cations with solid-state geometry and electronic structure unlike those of NHC-stabilized cations. Protection of the phosphorus atom in such ions with elemental sulfur provides an air- and moisture-stable dithiophosphinium salt.

Intramolecular stereoselective protonation of aldehyde-derived enolates

Picking sides: Asymmetric protonation of the titled compounds poses a most significant challenge and has been addressed by taking advantage of internal protonation and subsequent hemiacetal formation to avoid epimerization (see scheme). The substrates employed in these transformations can be easily accessed through a sequence of vinylogous aldol reactions with subsequent conjugate reductions.

Honeycomb sheet structures achieving high electrical conductivities in alkyl-substituted thiazolium bis(2-thioxo-1,3-dithiole-4,5-dithiolato) nickelate(III) complex salts

A series of [Ni(dmit)2] (1) (dmit = 2-thioxo-1,3-dithiole-4,5- dithiolato) complex salts with 3,4-dimethylthiazolium (2), 2,3,4- trimethylthiazolium (3), and 3,4,5-trimethylthiazolium (4) cations (I, II, and III, respectively) were synthesized and characterized by single-crystal X-ray analysis and conductivity. The molecular structures of 1 were the same in all three complex salts. In the structure of I, the anions were arranged in hexagonal structures. Neighboring hexagons formed honeycomb sheet structures as the result of S-S interactions in the (001) plane. The sheets of the honeycomb structures were arranged along the c axis with translational symmetries that form columnar honeycomb channels along the [111] direction. In the structures of II and III, honeycomb sheet structures were formed as in I. But in contrast to I, the relative position of the stacked sheets in II and III was slightly dislocated, forming zig-zag channels instead. The IR spectra of I, II, and III show that the C=C stretching band is slightly red-shifted to 1337-1339 from 1350 cm-1 for [Ni(dmit)2]-, caused by the partial oxidation of the anion. The measured values of the electrical conductivities were 0.20, 0.094, and 0.16 S cm-1 for I, II, and III, respectively. These high conductivities may be ascribed to the partially oxidation of the anion. The S-S interactions regulate the honeycomb sheet structure of the crystal and should work as conduction pathways effectively.

Reactivity of the Thiazolium C2 Ylide in Aprotic Solvents: Novel Experimental Evidence for Addition Rather Than Insertion Reactivity

Two thiazolium compounds were synthesized specifically labeled at their C2 positions: 3,4,5-trimethylthiazolium nitrate and 3-benzyl-5-(β-ethoxyethyl)-4-methylthiazolium bromide, with a view to examine their pathways leading to dimerization in strongly basic medium using 13C NMR.On addition of less than 1 equiv of base the N-methyl ion first formed an unsymmetrical dimer in which the C2 atoms of two molecules were bonded to each other and only one of them still carried a hydrogen; that unsymmetrical dimer upon addition of excess base lost the remaining hydrogen at C2 and was converted to a mixture of syn and anti symmetrical dimers in nearly equal amounts.The sequence of observations on addition of base to the N-methyl derivative is consistent with nucleophilic addition of the conjugate base to a second thiazolium ion at its C2 position.Since the unsymmetrical dimer is formed first, rather than the symmetrical dimer, the latter cannot result from direct dimerization of two conjugate bases (ylides) by a carbene mechanism.Instead, a carbanion-addition mechanism was further supported by two experiments.A "crossover" experiment was designed in which unsymmetrical dimers were detected in Me2SO on addition of limiting potassium tert-butoxide to thiazolium ions containing -H and -D, under conditions such that there was little H/D exchange observed at the C2 position.Also, N-3-alkenylthiazolium ions were synthesized, that, if carbenic reactivity had existed, would have resulted in formation of cyclopropanes.In preference to the intramolecular reaction, intermolecular unsymmetrical dimers resulted in each case, consistent with nucleophilic addition.On addition of base to the N-benzylthiazolium ion, the first product to be detected by 13C NMR was the syn/anti symmetrical dimer mixture (again bonded via the C2 atoms), that underwent a -sigmatropic rearrangement of one of the benzyl groups from N3 to C2.According to 1H NMR recorded within minutes of mixing, the unsymmetrical dimer precedes the symmetrical one for this salt as well.The reactivity of the C2 ylide derived from the N-methyl and N-benzylthiazolium ions can be rationalized according to an ionic addition reaction, implying that the related thiamin (vitamin B1) conjugate base (ylide) behaves similarly.

Mechanism of Base-catalysed Hydrogen-Deuterium Exchange in Thiazolium Ion: Evidence for the Involvement of a Tetrahedral Intermediate

The mechanism of base-catalysed hydrogen-deuterium exchange of 2-H in the thiazolium ion has been examined by 1H n.m.r. spectroscopy, using small and sterically hindered nucleophiles.Rapid H-D exchange is observed in Me2SO in the cases of 3,4,5-trimethyl- (1), 3-methyl-4,5-diphenyl- (2), 3,5-dimethyl-4-phenyl- (3), and 3,4-dimethyl-5-phenyl-thiazolium iodide (4), when small nucleophiles (KOD-D2O or KOCD3-DOCD3; 0.016M; 25 deg C) are employed.Utilization of a hindered nucleophile however results in a slow exhange of 2-H in (1), (3), and (4), concomitant with H-D exchange of the 4- and 5-methyl exchange of 2-H is detected in the case of (2) with the hindered nucleophile.These observations are ascribed to the formation of a tetrahedral intermediate as a prerequisite of the exchange reaction.