Differences in rates of Diels-Alder reactions as experimental indicators of synchronous or asynchronous transition states
作者:Ronald N Buckle、Pei-Ying Liu、Evan W.D Roberts、D.Jean Burnell
DOI:10.1016/s0040-4020(99)00667-5
日期:1999.9
Assessment of the relative rates of the Diels-Alder reactions of the unsymmetrical diene 2-(trimethylsilyloxy)-1,3-cyclohexadiene (1) and its 6,6- and 5,5-dimethyl analogs 2 and 3 indicated that with symmetrical, ethylenic dienophiles (para-benzoquinone, maleic anhydride and N-phenylmaleimide) the Diels-Alder reaction is almost synchronous, but with tetracyanoethylene and with diethyl acetylenedicarboxylate
对不对称二烯2-(三甲基甲硅烷氧基)-1,3-环己二烯(1)及其6,6和5,5-二甲基类似物2和3的Diels-Alder反应的相对速率进行了评估,结果表明,乙烯二烯亲二酮体(对-苯醌,马来酸酐和N-苯基马来酰亚胺)的Diels-Alder反应几乎是同步的,但对于四氰基乙烯和乙炔二羧酸二乙酯,添加的反应是足够异步的,从而导致与二甲基二烯2和3的反应速率不同。