作者:Nanyan Fu、Annette D. Allen、Shinjiro Kobayashi、Thomas T. Tidwell、Sinisa Vukovic、Selvananthan Arumugam、Vladimir V. Popik、Masaaki Mishima
DOI:10.1021/jo062090h
日期:2007.3.1
factor of 7.5 × 104, and the bis(Me2N) bisketene 14 is the most reactive in ring closure that has been reported. Rate constants for ring closure of these and previously observed bisketenes vary by a factor of 1013. The dialkylamino bisketenes 16 (R = Me, n-Bu) with tethered substituents and restricted geometries are less reactive than the bis(Me2N) bisketene 14 by factors of 1700 and 540, respectively
迄今为止,通过使用激光闪光光解法使相应的环丁二烯酮开环,已经生成了具有游离的(14)和束缚的(16)氨基取代基的未知的二氨基取代的双烯酮。通过红外或紫外光谱法测量氨基双烯酮回到环丁二烯的开环反应的时间分辨动力学,并给出一阶速率常数,其变化系数为7.5×10 4,而双(Me 2 N)据报道,双烯酮14在闭环中是反应性最强的。这些和先前观察到的双烯酮的闭环速率常数相差10 13倍。二烷基氨基双烯酮16(R = Me,具有束缚的取代基和受限制的几何形状的n- Bu)的反应性比双(Me 2 N)双烯酮14分别低1700和540倍。用DFT方法获得的计算结果表明,拴系的环丁二酮15中的角度应变会抑制双烯酮16的容易环化。