Electrophilic Cyclization of <i>o</i>-Acetoxy- and <i>o</i>-Benzyloxyalkynylpyridines: An Easy Entry into 2,3-Disubstituted Furopyridines
作者:Antonio Arcadi、Sandro Cacchi、Sabrina Di Giuseppe、Giancarlo Fabrizi、Fabio Marinelli
DOI:10.1021/ol0261581
日期:2002.7.1
[reaction: see text] 2,3-Disubstituted furo[3,2-b]pyridines, 2,3-disubstituted furo[2,3-b]pyridines, and 2,3-disubstituted furo[2,3-c]pyridines are readily prepared under mild conditions via the palladium-catalyzed cross-coupling of 1-alkynes with o-iodoacetoxy- or o-iodobenzyloxypyridines, followed by electrophilic cyclization by I(2) or by PdCl(2) under a balloon of carbon monoxide.
[反应:见正文] 2,3-二取代的呋喃[3,2-b]吡啶,2,3-二取代的呋喃[2,3-b]吡啶和2,3-二取代的呋喃[2,3-c]吡啶很容易在温和条件下制备,通过钯催化的1-炔与邻碘乙酰氧基-或邻碘苄氧基吡啶的偶联,然后在一氧化碳气球中通过I(2)或PdCl(2)进行亲电环化。