1, 3-Dipolar cycloaddition reaction of trimethylstannylacetylene with nitrile oxides yielded 3-substituted 5-(trimethylstannyl)isoxazoles. On the other hand, the same reaction of (trimethylstannyl)phenylacetylene, -1-hexyne, and -(trimethylsilyl)acetylene gave 3, 5-disubstituted 4-(trimethylstannyl)isoxazoles almost regioselectively. The regioselectivity of the cycloaddition reaction is interpreted by application of the frontier-electron theory.
三甲基锡乙炔与腈氧化物进行的1, 3-偶极环加成反应生成了3-取代的5-
三甲基锡异噁唑。另一方面,
三甲基锡苯乙炔、-
1-己炔和-(三甲基
硅基)
乙炔进行相同的反应,几乎区域选择性地得到了3, 5-二取代的4-
三甲基锡异噁唑。通过运用前沿电子理论来解释这种环加成反应的区域选择性。