The influence of the bulky trimethylsilyl substituent on the selectivity of metallation of dimethylaniline, anisole and 1-dimethylaminonaphthalene is studied. The neighboring SiMe₃ group forces dimethylamino and methoxy groups to occupy a conformation with an unshared electron pair turned towards silicon atom. This forced conformation prevents NMe₂ and OMe groups from providing the DOM-effect, thus facilitating meta-metallation with the use of bulky LiCKOR. While the inverted NMe₂ group completely suppresses ortho-metallation, the less bulky and more electron withdrawing OMe group demonstrates more rotation freedom allowing selective ortho-metallation with smaller reagents such as n-BuLi or tert-BuLi.

研究了庞大的三甲基甲硅烷基取代基对二甲基苯胺，苯甲醚和1-二甲基氨基萘金属化选择性的影响。相邻的SiMe ₃基团迫使二甲基氨基和甲氧基占据一个构象，其中未共享的电子对转向硅原子。这迫使构象防止NME ₂和OME组从提供所述DOM-效果，从而有利于元与使用笨重LiCKOR的-metallation。而反向的NME ₂组完全抑制邻-metallation中，体积更小且多个吸电子基团OME演示多个旋转自由度，允许选择性邻-metallation具有较小试剂如n -BuLi或叔-BuLi。