Synthese de pyrroles et d'oxazoles par pyrolyse de N-(hydroxy-2′ ethyl) amino-3 propenoate
作者:Catherine Pale-Grosdemange、Josselin Chuche
DOI:10.1016/s0040-4020(01)81018-8
日期:1989.1
pyrolysis of various N-(2′-hydroxyethyl)-3-amino propenoates 1–6 and N-(2′-hydroxy-2′-phenyl ethyl)-3-amino propenoate 7–9 at 390°–420°C leads respectively to formylpyrroles 11–16 and benzoylpyrroles 17–19 and, in some cases, to substituted oxazoles 36–39. The results are best explained by the intermediate formation of dicarbonyl derivative followed either by an intramolecular thermal crotonisation
C2-arylation of N-acyl pyrroles with arylhalides is developed for the first time using Pd(PPh3)4 as a catalyst in combination with Ag2CO3 under air, which allowed the application of a good compatibility catalytic system. This protocol provides a straightforward method for the preparation of valuable arylated pyrroles in moderate to good yields under the standard conditions with good substrate tolerance
N-酰基吡咯与芳基卤化物的C2-芳基化反应是首次使用Pd(PPh 3)4作为催化剂与Ag 2 CO 3组合在空气中进行的,这使得可应用良好相容性的催化体系。该方案提供了一种简单的方法,可在标准条件下以良好的底物耐受性以中等至良好的产率制备有价值的芳基化吡咯。有趣的是,尽管N-苯甲酰基吡咯反应良好,但使用具有噻吩或呋喃环的底物表明,对于本催化体系,噻吩和呋喃环比吡咯更具反应性。
HEXACARBONYLMOLYBDENUM- OR NONACARBONYLDIIRON-INDUCED REACTION OF 1,3-OXAZEPINE RING SYSTEM. EVIDENCE FOR THE VALENCE ISOMERIZATION BETWEEN 1,3-OXAZEPINE AND PYRIDINE-2,3-OXIDE
作者:Makoto Nitta、Tomoshige Kobayashi
DOI:10.1246/cl.1985.877
日期:1985.7.5
Upon treatment with [Mo(CO)6] or [Fe2(CO)9], phenyl-substituted 1,3-oxazepines undergo the C-2-O and C-7-O bond cleavage to give pyridine and pyrrole derivatives via a coordinated pyridine-2,3-oxide.