1-Aminobenzotriazole functionalisation using directed metallation: new routes to chromanes and chromenes using intramolecular benzyne trapping by alcohols
作者:David W. Knight、Paul B. Little
DOI:10.1039/b001834l
日期:——
Metallation of 1-(tert-butoxycarbonylamino)benzotriazole 8 leads to the dianionic species 9 which undergoes smooth reactions with a range of electrophiles, under appropriate conditions. The derived iodide 30 undergoes efficient Sonogashira coupling with a range of alk-1-yn-3-ols to provide the expected arylalkynes 33, total or partial reduction of which leads to the arylpropanols 34 and the (Z)-allylic alcohols 40 respectively. N-Deprotection and exposure to N-iodosuccinimide then led to smooth benzyne generation and intramolecular trapping by the hydroxy functions with iodine incorporation to give the iodochromanes 35 and iodochromenes 41 respectively, in respectable overall yields.
1-(tert-丁氧羰基氨基)苯并三氮唑8的金属化生成二负离子物种9,该物种在适当条件下与多种电亲体发生顺利反应。所得到的碘化物30与多种烷-1-炔-3-醇发生高效的Sonogashira偶联反应,提供了预期的芳基炔33,其中的完全或部分还原生成芳基丙醇34和(Z)-烯丙醇40。去保护N后,暴露于N-碘代琥珀酰亚胺下,顺利生成苯炔,并通过羟基功能进进行分子内捕捉,结合碘形成碘代色烯35和碘代色烯41,整体产率令人满意。