Reactions of indolizine-3-carbonitriles with dimethylacetylenedicarboxylate (DMAD), in the presence of Pd–C, gave the corresponding [2.2.3]cyclazines in low to moderate yields, whereas, in the absence of Pd–C, the same reactions afforded the 1 : 2 molar products. The X-ray analysis of one of the 1 : 2 adducts established that the structure was dimethyl 2-cyano-3-styrylpyrrole-1,4-dicarboxylate. A
CYCLOADDITION REACTION OF 3-CYANOINDOLIZINES WITH DIMETHYL ACETYLENEDICARBOXYLATE —FORMATION OF CYCL[3.2.2]AZINES AND 1:2 ADDUCTS
作者:Takane Uchida、Kiyoshi Matsumoto
DOI:10.1246/cl.1980.149
日期:1980.2.5
and (1b) react with dimethyl acetylenedicarboxylate in refluxing toluene in the presence of Pd–C to give the cycl[3.2.2]azines (4a) and (4b), respectively, while 3-cyano-7-methyl- and 3-cyano-7-benzylindolizines (1c) and (1d) affording the 1:2 adducts (6c) and (6d) along with cycl[3.2.2]azine (4d).