title: Synthesis of Pyrazolo[5,1-a]isoindoles and Pyrazolo[5,1-a]isoindole-3-carboxamides through One-Pot Cascade Reactions of 1-(2-Bromophenyl)buta-2,3-dien-1-ones with Isocyanide and Hydrazine or Acetohydrazide.
abstract: A novel and efficient method for the construction of the pyrazolo[5,1-a]isoindole scaffold via a one-pot three-component cascade reaction of 1-(2-bromophenyl)buta-2,3-dien-1-one with hydrazine and isocyanide promoted by a Pd catalyst is described. This cascade process proceeds through initial condensation of the allenic ketone with hydrazine followed by Pd-catalyzed isocyanide insertion into the C-Br bond and intramolecular C-N bond formation. Interestingly, when acetohydrazide was used in place of hydrazine, a more sophisticated procedure involving condensation, isocyanide insertion into C-H and C-Br bonds, deacetylation, and formation of C-C, C-O, and C-N bonds occurred to afford pyrazolo[5,1-a]isoindole-3-carboxamides with good efficiency.
authors.affiliation: School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, Henan Key Laboratory for Environmental Pollution Control, Henan Normal University, Xinxiang, Henan 453007, China.
authors.forename: Miaomiao
authors.initials: M
authors.lastname: Tian
authors.affiliation: School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, Henan Key Laboratory for Environmental Pollution Control, Henan Normal University, Xinxiang, Henan 453007, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: He
authors.affiliation: School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, Henan Key Laboratory for Environmental Pollution Control, Henan Normal University, Xinxiang, Henan 453007, China.
authors.forename: Xinying
authors.initials: X
authors.lastname: Zhang
authors.affiliation: School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, Henan Key Laboratory for Environmental Pollution Control, Henan Normal University, Xinxiang, Henan 453007, China.
authors.forename: Xuesen
authors.initials: X
authors.lastname: Fan
mesh_terms: D002384:Catalysis; D003486:Cyanides / Q000737:chemistry*; D006834:Hydrazines / Q000138:chemical synthesis* / Q000737:chemistry; D054833:Isoindoles / Q000138:chemical synthesis* / Q000737:chemistry; D015394:Molecular Structure; D010165:Palladium / Q000737:chemistry; D011720:Pyrazoles / Q000138:chemical synthesis / Q000737:chemistry
chemical_list: D003486:Cyanides; D006834:Hydrazines; D054833:Isoindoles; D011720:Pyrazoles; C000604321:pyrazolo(5,1-a)isoindole; C029424:hydrazine; D010165:Palladium