637-53-6Relevant articles and documents
Contribution of Solvents to Geometrical Preference in the Z/ E Equilibrium of N-Phenylthioacetamide
Chan, Erika S.,Hyodo, Tadashi,Ikeda, Hirotaka,Inagaki, Satoshi,Ohwada, Tomohiko,Otani, Yuko,Song, Shuyi,Tang, Yulan,Vu, Kim Anh L.,Yamaguchi, Kentaro
, (2021/06/28)
We studied the Z/E preference of N-phenylthioacetamide (thioacetanilide) derivatives in various solvents by means of 1H NMR spectroscopy, as well as molecular dynamics (MD) and other computational analyses. Our experimental results indicate that the Z/E isomer preference of secondary (NH)thioamides of N-phenylthioacetamides shows substantial solvent dependency, whereas the corresponding amides do not show solvent dependency of the Z/E isomer ratios. Detailed study of the solvent effects based on molecular dynamics simulations revealed that there are two main modes of hydrogen (H)-bond formation between solvent and (NH)thioacetamide, which influence the Z/E isomer preference of (NH)thioamides. DFT calculations of NH-thioamide in the presence of one or two explicit solvent molecules in the continuum solvent model can effectively mimic the solvation by multiple solvent molecules surrounding the thioamide in MD simulations and shed light on the precise nature of the interactions between thioamide and solvent. Orbital interaction analysis showed that, counterintuitively, the Z/E preference of NH-thioacetamides is mainly determined by steric repulsion, while that of sterically congested N-methylthioacetamides is mainly determined by thioamide conjugation.
Iodoalkyne-Based Catalyst-Mediated Activation of Thioamides through Halogen Bonding
Matsuzawa, Akinobu,Takeuchi, Shiho,Sugita, Kazuyuki
supporting information, p. 2863 - 2866 (2016/10/25)
Halogen bonding catalysis has recently gained increasing attention as a powerful tool to activate organic molecules. However, the variety of the catalyst structure has been quite limited so far. Herein, we report the first example of the use of an iodoalkyne as a halogen bond donor catalyst. By using an iodoalkyne bearing a pentafluorophenyl group as a catalyst, thioamides were efficiently activated and reacted with 2-aminophenol to generate benzoxazoles in good yield. Mechanistic studies, including 13C NMR spectroscopic analysis and several control experiments, provided concrete evidence that this catalytic activation is based on halogen bonding. Thus, the results obtained in this study demonstrate that iodoalkynes can serve as a new scaffold for future development of halogen bonding catalysis.
Organocatalytic, difluorocarbene-based S-difluoromethylation of thiocarbonyl compounds
Fuchibe, Kohei,Bando, Masaki,Takayama, Ryo,Ichikawa, Junji
, p. 133 - 138 (2015/03/04)
Upon treatment with trimethylsilyl 2,2-difluoro-2-fluorosulfonylacetate (TFDA) and a catalytic amount of N,N,N′,N′-tetramethyl-1,8-diaminonaphthalene, secondary thioamides and thiocarbamates undergo selective difluoromethylation on the sulfur atom to give S-difluoromethyl thioimidates and thioiminocarbonates in good yields, respectively. This is the first report on the synthesis of acyclic difluoromethyl thioimidates and thioiminocarbonates. The key for S-difluoromethylation is the organocatalytic generation of difluorocarbene (:CF2) under mild conditions, which prevents decomposition of the substrates. This process provides an efficient approach to pharmaceuticals and agrochemicals bearing a difluoromethylsulfanyl group, starting from widely available thiocarbonyl compounds.