Synthesis of 3,1-Benzoxazines from N-Substituted ortho-(Cycloalk-1-enyl or alk-2-en-2-yl)anilines

New derivatives of 3,1-benzoxazine have been synthesized by the cyclization of RCO-substituted at the nitrogen atom (R = OEt, Me, NH₂) ortho-(cycloalk-1-enyl or alken-1-yl)anilines under mild conditions.     

Synthesis of Fluorogenic Arylureas and Amides and Their Interaction with Amines: A Competition between Turn-on Fluorescence and Organic Radicals on the Way to a Smart Label for Fish Freshness

We describe the synthesis of fluorogenic arylureas and amides and their interaction with primary or secondary amines under air and light in organic-aqueous mixtures to give rise to a new class of persistent organic radicals, described on the basis of their electron paramagnetic resonance (EPR), as well as UV–vis, fluorescence, NMR, and quantum mechanics calculations, and their prospective use as multi-signal reporters in a smart label for fish freshness.     

钯催化芳基偶氮的氧化羰基化反应

采用TBHP作为氧化剂,发展了钯催化芳基偶氮化合物N＝N双键断裂的氧化羰基化反应.芳基偶氮的羰基化反应在Pd(OAc)2(5％),MeO-BIPHEP (5％),芳基偶氮(0.2 mmol),TBHP(2 equiv),H2O(1 equiv),DCE(1 mL),CO (3.0 MPa)的条件下110℃反应12h后,经柱层析纯化分离得到31％-91％的芳基脲.初步的机理研究表明,芳基偶氮化合物的N＝N双键断裂原位产生芳基胺,再进一步氧化羰基化生成芳基脲.