Efficient synthesis of unsaturated seven-membered rings by an entropy/strain reduction strategy: 2,7-dihydro-1H-azepines, -oxepines, -thiepines, -1H-phosphepine and 1,3-cycloheptadienes
作者:James G. Walsh、Patrick J. Furlong、Declan G. Gilheany
DOI:10.1039/c39940000067
日期:——
Substituted (Z,Z)-1,6-dibromohexa-2,4-dienes, obtained from substituted catechols via the corresponding diols, react with primary amines, lithium sulfide, sodium phenylphosphide and malonic ester enolate under mild conditions to give efficient syntheses of 2,7-dihydro-1H-azepines, 2,7-dihydrothiepines, 2,7-dihydro-1H-phosphepine and cyclohepta-1,3-dienes respectively while the precursor diols yield the 2,7-dihydrooxepines on treatment with toluene-p-sulfonyl chloride.
替代的(Z,Z)-1,6-二溴己-2,4-二烯,由相应的二醇从替代的儿茶酚获得,在温和条件下与一胺、硫化锂、苯基膦化钠和马隆酸酯烯醇反应,分别有效合成2,7-二氢-1H-氮杂庚烯、2,7-二氢-噻吡啶、2,7-二氢-1H-膦烯和环己-1,3-二烯,而前体二醇在与对甲苯磺酰氯处理时产生2,7-二氢噁庚烯。