作者:Thomas Müller、Christian Bauch、Markus Ostermeier、Michael Bolte、Norbert Auner
DOI:10.1021/ja021234g
日期:2003.2.1
(4i)) and the small J coupling constants between the element and the remote vinyl carbons in the case of 4h and 4i (J(CSn) = 26 Hz, J(CPb) = 16 Hz) give experimental evidence for the intramolecular interaction and the charge transfer between the positively charged element and the remote C=C double bond. The experimental results are supported by quantum mechanical calculations of structures, energies, and
14 族元素 Si --> Pb 的降冰片基阳离子已从取代的 3-环戊烯甲基前体通过将瞬时阳离子分子内加成到 3-环戊烯甲基取代基的 C=C 双键(pi-路线到降冰片基阳离子)合成。降冰片基阳离子 4a (E = Si, R = Me), 4e (E = Si, R = Et), 4f (E = Si, R = Bu), 4g (E = Ge, R = Bu), 4h (E = Sn, R = Bu) 和 4i (E = Pb, R = Et) 已通过其特征 NMR 化学位移 (4a,e,f, delta((29)Si) = 80-87, delta((( 13)C)(CH=) = 149.6-150.6; 4g, delta((13)C)(CH=) = 144.8; 4h, delta((119)Sn) = 334, delta((13)C)(CH =) = 141.5; 4i, delta((207)Pb)