A Homologous Series ofO- andN-Functionalized 2,2-Difluoro1,3-benzodioxoles: an Exercise in Organometallic Methodology
作者:Manfred Schlosser、Joanna Gorecka、Eva Castagnetti
DOI:10.1002/ejoc.200390079
日期:2003.2
The conversion of 2,2-difluoro-1,3-benzodioxole, an exceptionally acidic arene, via a 4-lithiated intermediate into more than three dozen new derivs. was conceived as a case study. The lithiated species was trapped by C0-electrophiles (4-toluenesulfonyl azide, fluorodimethoxyborane, iodine), C1-electrophiles (carbon dioxide, N,N-dimethylformamide, formaldehyde, di-Me sulfate), C2-electrophiles (oxalic
2,2-二氟-1,3-苯并二氧杂环戊烯(一种异常酸性的芳烃)通过 4-锂化中间体转化为三打以上的新衍生物。被认为是一个案例研究。锂化物质被 C0-亲电试剂(4-甲苯磺酰叠氮化物、氟二甲氧基硼烷、碘)、C1-亲电试剂(二氧化碳、N,N-二甲基甲酰胺、甲醛、二甲基硫酸盐)、C2-亲电试剂(草酸二酯、环氧乙烷)捕获)、C3-亲电试剂(氧杂环丁烷)和高级烷基碘。所得羧酸2,2-二氟-1,3-苯并二氧杂环戊烯-4-羧酸可用有机锂化合物处理。得到酮和醛 2,2-difluoro-1,3-benzodioxole-4-carboxaldehyde 可以在碱性条件下与硝基甲烷或乙酸酐缩合。如果没有用三氧化铬氧化成相应的羧酸,则化合物,例如,4-(3-羟丙基)-2,2-difluoro-1,3-benzodioxole 可以转化为相应的溴化物或磺酸盐。他们与氮contg缩合。C0-亲核试剂(羟胺、叠氮化钠、