Synthesis of Polysubstituted 5-Aminooxazoles from α- Diazocarbonyl Esters and α-Isocyanoacetamides
摘要:
A novel and efficient reaction for the synthesis of 2-keto-5-aminooxazoles is developed. The entire sequence is realized by simply heating a xylene solution of alpha-diazocarbonyl esters and alpha-isocyanoacetamides without any promoters. A possible mechanism for the entire sequence is proposed.
Construction of Multifunctionalized Azopyrazoles by Silver- Catalyzed Cascade Reaction of Diazo Compounds
作者:Rameshwar Prasad Pandit、Yong Rok Lee
DOI:10.1002/adsc.201500197
日期:2015.8.24
silver trifluoromethanesulfonate (AgOTf)‐catalyzed cascade reaction of α‐diazo‐β‐keto esters with two arylhydrazines or two arylhydrazine hydrochlorides. This cascade reaction included pyrazolone formation, NHinsertion, and oxidation. For the synthesis of more diverse azopyrazoles bearing two different aromatic rings, the silver(I)‐catalyzed cascade reaction of 4‐diazopyrazol‐3‐one with arylhydrazine
A novel Zn(OAc)2-catalyzed three-component tandem cyclization reaction of isocyanides, α-diazoketones and anhydrides has been developed. The reaction demonstrates the wide scope of substrates and provides a novel and efficient strategy for the synthesis of polysubstituted maleimides from readily available substrates in a single step.
Taking diazo transfer to water: α-diazo carbonyl compounds from in situ generated mesyl azide
作者:Robert M. Shevalev、Petr A. Zhmurov、Dmitry V. Dar’in、Mikhail Krasavin
DOI:10.1016/j.mencom.2020.05.037
日期:2020.5
Mesylazide generated in situ in aqueous medium converted a range of active methylene substrates into the corresponding diazo compounds in good yields and high purity with no need for chromatographic purification. The products thus obtained are suitable for the subsequent RhII-catalyzed O–H insertions with no need for chromatography in the interim.
Rhodium-catalyzed tunable oxidative cyclization toward the selective synthesis of α-pyrones and furans
作者:Jiaping Wu、Dongxu Wang、Yanjun Wan、Cheng Ma
DOI:10.1039/c5cc09137c
日期:——
tunable oxidative cyclization of readily available N-tosylacrylamides and diazo compounds is presented, which offeres a novel method for the selective construction of fully substituted [small alpha]-pyrones and furans in...
for the synthesis of 12H-indazolo[2,1-a]cinnolin-12-ones was developed. Significantly, a less developed cationic complex [Ru(p-cymene)(MeCN)3(SbF6)2] was found to be effective for this transformation. In this reaction, a tandem pathway of C–H ruthenation, Ru(II)–carbene formation, migratory insertion and condensation was involved. The results of a primary mechanistic study suggested that the C–H activation
开发了一种鲁棒,高效且可扩展的合成12 H-吲哚并[2,1 - a ] cinnolin-12-ones的方法。重要的是,发现欠发达的阳离子络合物[Ru(对-cymene)(MeCN)3(SbF 6)2 ]对这种转化有效。在该反应中,涉及到了C–H钌化,Ru(II)–卡宾形成,迁移插入和缩合的串联途径。初步机理研究的结果表明,C–H活化过程可能遵循亲电型金属化/去质子化机理。