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Domino β‐C−H Functionalization and [3+2] Cycloaddition for Efficient Synthesis of Diverse Spiro and Polycyclic Compounds
Author(s) -
Fang HuiLin,
Han Ying,
Sun Jing,
Yan ChaoGuo
Publication year - 2020
Publication title -
chemistryselect
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 34
ISSN - 2365-6549
DOI - 10.1002/slct.202003342
Subject(s) - pyrrolidine , chemistry , surface modification , toluene , cycloaddition , domino , cascade reaction , conjugated system , acetic acid , pyrimidine , medicinal chemistry , organic chemistry , combinatorial chemistry , catalysis , stereochemistry , polymer
The acetic acid catalyzed three‐component reaction of pyrrolidine, aromatic aldehydes and 4‐arylidene‐5‐methyl‐2‐phenylpyrazol‐3‐one in refluxing toluene gave functionalized 7′‐( E )‐benzylidenespiro[pyrazole‐4,1′‐pyrrolizines] in good yields and with high diastereoselectivity. The similar reaction with 2‐arylidene‐ N,N’ ‐dimethylbarbiturates resulted in mixture of Z/E ‐isomers of 7′‐ arylidenespiro[pyrimidine‐5,1′‐pyrrolizines] in good yields. However, the three‐component with N ‐phenylmaleimides and sequential oxidation with DDQ reaction gave 8‐( E )‐arylidenedihydropyrrolo[3,4‐ a ]pyrrolizines in satisfactory yields. The reaction mechanism included sequential β‐C−H functionalization of pyrrolidine, generation of conjugated azomethine ylides, and sequential [3+2] cycloaddition with active alkenes.