| Research Abstract |
In the course of development of new reactions, new asymmetric induction reactions, and new seed compounds toward drugs, we have found several non-bonded interactions such as S…O, S…N, S…S, S…π, π…π, CH…π, and CH…O in the crystallographic structures of many compounds. Since we have established an intramolecular non-bonded S…O interaction in the molecules of angiotensin II receptor antagonists and a new carbapenem antibiotic, biapenem, we have revealed many kinds of intramolecular non-bonded S…X (S = O, N, S) interactions in newly designed and synthesized organosulfur compounds by utilizing X-ray crystallographic analysis and ab initio MO calculation. Specifically, the S…S interaction was recognized in the compounds obtained from desulfurirative self-coupling reaction of achiral and chiral 1,3-thiazolidine-2-thiorie derivatives. Remarkable discrepancy in the predominant structures of acyl(or thioacyl) aminothiadiazoles, acyl(or thioacyl) aminooxadiazoles, and the related compounds was cl
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arified by utilizing X-ray crystallographic analyses and ab initio MO calculation. Unique and novel intramolecular non-bonded O…S…X (X = F, Cl, Br) interactions have also recognized in the X-ray crystallographic structures of 2-acylimino-5-(2-halophenyl)- 1, 3, 4- thiadiazoline derivatives, and it was clarified in terms of the ab initio MO calculation of the model compounds that the structure bearing an S…halogen interaction is most stable in their possible rotational isomers. In order to create new reaction media, new functional materials, and new drugs, mono-, bi-, tri-thiazoles and firefly luciferin-like compounds were synthesized. In these compounds, non-bonded S…X (X = O, S, N, Br) interactions were similarly established. Highly chemo- and stereoselective asymmetric Pummerer reactions were developped by utilizing inter molecular non-bonded S…O interaction between chiral sulfoxides and amide solvents. Syntheses of new carbapenem antibiotics bearing acyliminothiadiazolines as the pendant moiety, were successfully achieved. Less
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