Transition Metal-Free Visible Light-Driven Photoredox Oxidative Annulation of Arylamidines
摘要:
A fast catalytic synthesis of multisubstituted quinazolines from readily available amidines via visible light-mediated oxidative C(sp(3))-C(sp(2)) bond formation has been established. This reaction is a metal-free oxidative coupling catalyzed by a photoredox organocatalyst. The protocol features low catalyst loading (1 mol %).
Efficient Microwave Access to Polysubstituted Amidines from Imidoylbenzotriazoles
摘要:
Microwave reactions of primary and secondary amines with imidoylbenzotriazoles 6a-w gave diversely substituted amidines 7a-Aa in 76-94% yields. Convenient preparations of a variety of amides 5a-Ab (87-96%) and imidoylbenzotriazoles 6a-w (56-95%) have also been developed using microwave irradiation under mild conditions and short reaction times. These results demonstrate further the advantages of microwave synthesis and introduce a new application of imidoylbenzotriazoles in the preparation of polysubstituted amidines.
mild diethylaminosulfur trifluoride/tetrahydrofuran (DAST–THF) system affords imidoyl fluorides. These compounds were isolated, and their structures were confirmed by X-ray single-crystal structure analysis. Reaction of imidoyl fluorides with various nucleophiles efficiently afforded amides, amidines, thioamides, and amine derivatives in high yields. Furthermore, one-pot reaction of in situ generated
用相对温和的二乙氨基三氟化硫/四氢呋喃 (DAST–THF) 系统氟化肟,得到亚氨基氟化物。这些化合物被分离出来,并通过 X 射线单晶结构分析确定了它们的结构。亚氨基氟化物与各种亲核试剂的反应有效地以高产率提供酰胺、脒、硫代酰胺和胺衍生物。此外,由肟原位生成亚氨基氟化物的一锅法反应也适用于这些产品的高效合成。肟立体化学和酸不稳定保护基在该系统中保持完整。