Electronic Effects and the Stereochemistries in Rearrangement−Displacement Reactions of Triaryl(halomethyl)silanes with Fluoride and with Alkoxide Ions
作者:John M. Allen、Steve L. Aprahamian、Esther A. Sans、Harold Shechter
DOI:10.1021/jo010471j
日期:2002.5.1
reacts with (halomethyl)diphenyl(para-substituted-phenyl)silanes (13, X = Cl), 14 (X = Br), and 15 (X = I) in ether solvents to give fluorodiphenyl(para-substituted-phenylmethyl)silanes (17a) and fluorophenyl(phenylmethyl)(para-substituted-phenyl)silanes (20a) by attack on silicon and migrations of the phenyl or the para-substituted-phenyl groups to C-1 with displacement of chloride ion. Sodium methoxide
四丁基氟化铵(TBAF)在醚溶剂中与(卤代甲基)二苯基(对位取代苯基)硅烷(13,X = Cl),14(X = Br)和15(X = I)反应生成氟代二苯基取代的苯基甲基)硅烷(17a)和氟苯基(苯基甲基)(对取代的苯基)硅烷(20a)受到硅的侵蚀以及苯基或对取代的苯基向氯离子的迁移而迁移到C-1 。二恶烷中的甲醇钠会引起14(X = Br)的重排,从而生成甲氧基二苯基(对位取代的苯基甲基)硅烷(17b)和甲氧基苯基(对苯基甲基)(对位取代的苯基)硅烷(20b)。25°C下F(-)在13的重排-位移中变化的苯基的迁移倾向为p-CF(3)-Ph,2.72> p-Cl-Ph,1.67> Ph,1.00> p-CH (3)-Ph,0.91>对-CH(3)O-Ph,0。58> p-(CH(3))(2)N-Ph,0.55。对于14与甲醇钠在二恶烷中的反应,在23°C时的迁移能力为p-CF(3)-Ph,2