Maryam Miri, Avat Arman Taherpour* and Curt Wentrup*,
{"title":"Nitrile Imine Cyclizations and Rearrangements: N-Phenyl-C-styrylnitrile Imine and N-Phenyl-C-phenylethynylnitrile Imine","authors":"Maryam Miri, Avat Arman Taherpour* and Curt Wentrup*, ","doi":"10.1021/acs.joc.4c00570","DOIUrl":null,"url":null,"abstract":"<p >The formation and rearrangements of nitrile imines are of ongoing synthetic and theoretical interest. In this paper, we report a computational investigation at the M06/6-311 + G(d,p) level of the formation and rearrangement of propargylic <i>N-</i>phenyl<i>-C-</i>styrylnitrile imine <b>3</b> from 2-phenyl-5-styryltetrazole <b>1</b> by flash vacuum pyrolysis (FVP). Nitrile imine <b>3</b> cyclizes to 3a<i>H</i>-3-styrylindazole <b>4</b>, which is also generated by H-shifts in the FVP of 3-styrylindazole <b>8</b>. Tautomerization of <b>4</b> and N<sub>2</sub>-elimination afford cyclohexadienylidene <b>14</b>, which by cyclization followed by H-shifts yields the primary pyrolysis product, 3-phenylindene <b>5</b>. An alternate path via 7a<i>H</i>-3-styrylindazole, phenyl(styryl)diazomethane, and phenyl(styryl)carbene is potentially possible. The analogous pyrolysis of 2-phenyl-5-phenylethynyltetrazole <b>1′</b> afforded cyclopenta[<i>fg</i>]fluorene and cyclopenta[<i>def</i>]phenanthrene via <i>N</i>-phenyl-<i>C</i>-phenylethynylnitrile imine <b>3′</b> and 3a<i>H</i>-3-phenylethynylindazole <b>4′</b>. In both cases, <b>3</b> and <b>3′</b>, rearrangement to diazocyclohexadienes and cyclohexadienylidenes (e.g., <b>14</b>) is energetically preferred over alternate aryldiazomethane and arylcarbene intermediates.</p>","PeriodicalId":57,"journal":{"name":"The Journal of Organic Chemistry","volume":null,"pages":null},"PeriodicalIF":3.3000,"publicationDate":"2024-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"The Journal of Organic Chemistry","FirstCategoryId":"1","ListUrlMain":"https://pubs.acs.org/doi/10.1021/acs.joc.4c00570","RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, ORGANIC","Score":null,"Total":0}
引用次数: 0
Abstract
The formation and rearrangements of nitrile imines are of ongoing synthetic and theoretical interest. In this paper, we report a computational investigation at the M06/6-311 + G(d,p) level of the formation and rearrangement of propargylic N-phenyl-C-styrylnitrile imine 3 from 2-phenyl-5-styryltetrazole 1 by flash vacuum pyrolysis (FVP). Nitrile imine 3 cyclizes to 3aH-3-styrylindazole 4, which is also generated by H-shifts in the FVP of 3-styrylindazole 8. Tautomerization of 4 and N2-elimination afford cyclohexadienylidene 14, which by cyclization followed by H-shifts yields the primary pyrolysis product, 3-phenylindene 5. An alternate path via 7aH-3-styrylindazole, phenyl(styryl)diazomethane, and phenyl(styryl)carbene is potentially possible. The analogous pyrolysis of 2-phenyl-5-phenylethynyltetrazole 1′ afforded cyclopenta[fg]fluorene and cyclopenta[def]phenanthrene via N-phenyl-C-phenylethynylnitrile imine 3′ and 3aH-3-phenylethynylindazole 4′. In both cases, 3 and 3′, rearrangement to diazocyclohexadienes and cyclohexadienylidenes (e.g., 14) is energetically preferred over alternate aryldiazomethane and arylcarbene intermediates.
期刊介绍:
The Journal of Organic Chemistry welcomes original contributions of fundamental research in all branches of the theory and practice of organic chemistry. In selecting manuscripts for publication, the editors place emphasis on the quality and novelty of the work, as well as the breadth of interest to the organic chemistry community.