作者:Alan R. Katritzky、Clara N. Fali、Jianqing Li
DOI:10.1021/jo9710846
日期:1997.11.1
2-(benzotriazol-1-ylmethyl)benzo[b]furan (12). The benzotriazolyl-CH(2) side chain of 12 was further elaborated by (i) alkylation with trans-cinnamaldehyde to give the adduct 14, followed by intramolecular cyclization to give dibenzofuran 17; (ii) alkylation with benzyl bromide followed by elimination or nucleophilic displacement of the benzotriazolyl moiety with Grignard reagent and subsequent dehydrogenation
用正丁基锂然后用各种α,β-不饱和酮和醛处理2-(苯并三唑-1-基甲基)呋喃4a-c,得到加合物6a-f,将其分子内环化形成取代的苯并[b]呋喃10a-f。4a-c的锂化和随后的烷基化得到中间体8a-c,该中间体用α,β-不饱和酮或醛进行类似的转化,得到相应的多取代的苯并[b]呋喃7a-c。在(PPh(3))(2)PdCl(2),CuI和Et(3)N存在下,邻碘苯酚(11)与1-炔丙基苯并三唑(1)生成2-(苯并三唑-1-基甲基)苯并[b]呋喃(12)。通过(i)用反式肉桂醛烷基化进一步形成加成物12的苯并三唑基-CH(2)侧链,得到加合物14,随后分子内环化得到二苯并呋喃17;(ii)用苄基溴烷基化,然后用格氏试剂消除或亲核取代苯并三唑基部分,随后脱氢分别得到2-烯基苯并呋喃15或20;(iii)用(CH(3))(3)CCHO烷基化,然后低价钛促进的烯烃化,得到烯烃19;(iv)用苯甲醛