Inter- and intra-molecular N-alkylation of α-halocarboxamides and dihalocarboxamides in the presence of solid phase transfer catalyst led to the corresponding piperazine-2,5-diones (2) and lactams (4) in the yields of 64–88 and 63–99%, respectively. A one-pot synthesis of β-lactams (7) from α-methyl-α,β-dibromopropionyl chloride (5) and α-amino acid using phase transfer catalyst was also successfully achieved.
centers. The broad functionalgroup compatibility highlights the mildness of the present catalysis. Notably, we achieved successive β-functionalization and oxidation of aminoacid Schiff bases to afford dehydroalanine derivatives bearing tetrasubstituted carbon. A three-component cross-coupling reaction of an aminoacid Schiff base, alkyl bromides, and styrene derivatives demonstrated the high utility
Hydroalkylation of Alkynes: Functionalization of the Alkenyl Copper Intermediate through Single Electron Transfer Chemistry
作者:Avijit Hazra、Jonathan A. Kephart、Alexandra Velian、Gojko Lalic
DOI:10.1021/jacs.1c03396
日期:2021.6.2
of terminal alkynes and α-bromo carbonyls to generate functionalized E-alkenes. The coupling is accomplished by merging the closed-shell hydrocupration of alkynes with the open-shell single electron transfer (SET) chemistry of the resulting alkenyl copper intermediate. We demonstrate that the reaction is compatible with various functional groups and can be performed in the presence of aryl bromides,
我们开发了一种末端炔烃和α-溴羰基立体选择性偶联生成官能化E-烯烃的方法。偶联是通过将炔烃的闭壳氢化铜化与所得烯基铜中间体的开壳单电子转移 (SET) 化学相结合来实现的。我们证明该反应与各种官能团相容,并且可以在芳基溴、烷基氯、烷基溴、酯、腈、酰胺和多种含氮杂环化合物的存在下进行。机理研究为通过 α-溴酯对烯基铜中间体进行 SET 氧化提供了证据,这是实现交叉偶联的关键步骤。
Okawara, Tadashi; Matsuda, Takashi; Furukawa, Mitsuru, Chemical and pharmaceutical bulletin, 1982, vol. 30, # 4, p. 1225 - 1233