1-Aminobenzotriazole functionalisation using directed metallation: new routes to chromanes and chromenes using intramolecular benzyne trapping by alcohols
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.
Double deprotonation of N-Boc-aminobenzotriazole for the preparation of substituted benzyne precursors
作者:K.Y.Li Stanley、David W. Knight、Paul B. Little
DOI:10.1016/0040-4039(96)01139-2
日期:1996.7
converted into its N,7-dilithio derivative 7 which can be trapped by a variety of electrophiles at the 7-position to give a number of new aminobenzotriazoles suitable for the generation of substituted benzynes.