495-45-4Relevant articles and documents
Novel synthesis of oxadiazinone and oxadiazepinone derivatives by ring expansion of diaziridinone
Komatsu, Mitsuo,Sakai, Norio,Hakotani, Akira,Minakata, Satoshi,Ohshiro, Yoshiki
, p. 541 - 544 (2000)
Treatment of N, N'-di-tert-butyldiaziridinone with α-hydroxy ketones in the presence of a catalytic amount of BF3·OEt2 gave carbazate derivatives in excellent yields. Acid-catalyzed recyclization of these compounds easily proceeded to give oxadiazinone derivatives. The reaction was applicable to the synthesis of oxadiazepinone derivatives and also to one-pot process.
Rearrangement of dypnones to 1,3,5-triarylbenzenes
Deng, Kai,Huai, Qi-Yong,Shen, Zhi-Lun,Li, Hui-Jing,Liu, Chen,Wu, Yan-Chao
, p. 1473 - 1476 (2015)
Rearrangement of dypnones to 1,3,5-triarylbenzenes is described. The reaction is proposed to involve an aldol-type self-condensation of dypnones, followed by an intramolecular [2 + 2] cycloaddition and a retro-[2 + 2] cycloaddition. The reaction goes smoothly under obviously milder conditions in comparison to the cyclotrimerization of acetophenones to 1,3,5-triarylbenzenes (10 mol % of TsOH, 80 °C versus 130-148 °C). This unexpected rearrangement would provide new possible considerations in dypnone-involved organic synthesis.
Visible Light Mediated Photocatalytic N-Radical Cascade Reactivity of O,δ-Unsaturated N-Arylsulfonylhydrazones: A General Approach to Structurally Diverse Tetrahydropyridazines
Azzi, Emanuele,Ghigo, Giovanni,Parisotto, Stefano,Pellegrino, Francesco,Priola, Emanuele,Renzi, Polyssena,Deagostino, Annamaria
, p. 3300 - 3323 (2021/02/16)
Tetrahydropyridazines are of particular interest for their versatility as intermediates in organic synthesis and display pharmacological activity in several domains. Here, we describe the photocatalytic synthesis of different tetrahydropyridazines starting from O,δ-unsaturated N-arylsulfonylhydrazones. Simple structural changes of substrates result into three different pathways beginning from a common N-hydrazonyl radical, which evolves through a domino carboamination/dearomatization, a HAT process, or a photoinduced radical Smiles rearrangement to afford diverse tetrahydropyridazines. All reactions are carried out in very mild conditions, and the quite inexpensive [Ru(bpy)3]Cl2 is used as the catalyst. Preliminary mechanism studies are presented, among them luminescence and electrochemical characterization of the involved species. Computational studies allow to rationalize the mechanism in accord with the experimental findings.
Highly Enantioselective Iridium-Catalyzed Hydrogenation of Conjugated Trisubstituted Enones
Peters, Bram B. C.,Jongcharoenkamol, Jira,Krajangsri, Suppachai,Andersson, Pher G.
, p. 242 - 246 (2021/01/13)
Asymmetric hydrogenation of conjugated enones is one of the most efficient and straightforward methods to prepare optically active ketones. In this study, chiral bidentate Ir-N,P complexes were utilized to access these scaffolds for ketones bearing the stereogenic center at both the α- and β-positions. Excellent enantiomeric excesses, of up to 99%, were obtained, accompanied with good to high isolated yields. Challenging dialkyl substituted substrates, which are difficult to hydrogenate with satisfactory chiral induction, were hydrogenated in a highly enantioselective fashion.