作者:Michael Winkler、Bayram Cakir、Wolfram Sander
DOI:10.1021/ja039142u
日期:2004.5.1
kcal mol(-1). In contrast to 3,5-borabenzyne (2), which is found to be doubly aromatic, nucleus-independent chemical shifts of 3 are almost identical to that of pyridine, indicating the absence of paramagnetic ring current effects that may be associated with "in-plane antiaromaticity". As compared with 1, the overall perturbation caused by the nitrogen atom in 3 is weak, and four electron, three center
3,5-吡啶 (3) 是通过 3,5-二碘吡啶 (20) 和 3,5-二硝基吡啶 (21) 的快速真空热解生成的,并通过低温氩基质中的红外光谱表征。芳炔可以通过其在 254 nm 处的光稳定性与其他副产物清楚地区分,诱导快速开环,推测为 (Z)-1-aza-hex-3-ene-1,5-diyne。作为热解的副产物,HCN 和丁二炔以及痕量的乙炔、氰基乙炔、(E)-1-aza-hex-3-ene-1,5-diyne 和 3-iodo-5-pyridyl 自由基被鉴定出来(从 20)。已经通过密度泛函理论和 ab initio 量子化学方法在计算上探索了 3 和母体间苄 (1) 重排和断裂的几种途径。双自由基1和3的最低能量分解途径是伴随氢迁移的开环过程,导致(Z)-hex-3-ene-1,5-二炔[(Z)-10]和(Z)-分别为 3-aza-hex-3-ene-1,5-diyne [(Z)-24]。这两种反应都需要