Activation of Olefins with Polarity Inversion and Its Synthetic Application

为碳-碳不饱和键引入官能团的反应作为构建有机分子的有效方法在有机合成中得到了广泛的应用。作为这种转化的一种方法，已经开发了一些使用过渡金属催化剂的反应，但在许多情况下，已经使用了后过渡金属催化剂。本研究的主要目的是利用早期过渡金属络合物的特性开发新的催化反应。在格氏试剂的存在下，末端烯烃通过与氯硅烷的反应进行硅烷化反应，使用催化量的二氯二茂锆来生成烯基和/或烯丙基硅烷。当用硅基硫化物、硅基硒化物和硅基碲化物代替氯硅烷时，反应也可以在温和的条件下进行。作为这一反应的延伸，以一种含β-氢的烷基对甲苯磺酸盐、硫酸盐和溴化物为催化剂，通过区域选择性烷基化反应，发展了一种新的芳基烯烃转化反应。当反应在茂钛催化剂上进行时，芳烃在四氢呋喃中进行双烷基化反应，得到1，2-Vic-二烷基产物。另一方面，芳基烯烃与烷基溴在乙醚中的Heck型转化也是在相似条件下进行的。还研究了1，3-丁二烯与氯硅烷和/或烷基溴化物的羧硅化和双硅烷化反应。该反应在温和的条件下进行，在钛茂催化剂的存在下，生成1，4-羧基硅烷或1，4-双硅烷基2-丁烯。在类似的条件下，芳基取代的烯烃也可以得到1，2-羧基硅化或1，2-双硅烷化产物。

The reactions which introduce functionalities to carbon-carbon unsaturated bonds have been widely used for organic syntheses as useful methods for the construction of organic molecules. As one methodology for such transformations, there have been developed a number of reactions using a transition metal catalyst, but in many cases the late transition metal catalysts have been employed. The main object of the present studies is to develop new catalytic reactions using the characteristics of early transition metal ate complexes. Terminal alkenes undergo silylation by the reaction with chlorosilanes in the presence of a Grignard reagent employing a catalytic amount of zirconocene dichloride to give alkenyl and/or allylsilanes as the products. The reaction also proceeds under mild conditions when silyl sulfides, silyl selenides, and silyl tellurides are used in place of chlorosilanes. As an extension of this reaction, a new transformation of aryl alkenes via regioselective alkylation using alkyl tosylates, sulfates and bromides having a β-hydrogen has been developed using a zirconocene complex as the catalyst. When the reaction was carried out using tianocene catalyst, double alkylation of aryl alkenes proceeds in THF to give 1,2-vic-dialkylated products. On the other hand, Heck type transformation of aryl alkenes with alkyl bromides proceeds in ether under similar conditions. Carbosilylation and double silylation of 1,3-butadienes with chlorosilanes and/or alkyl bromides were also developed. This reaction proceeds under mild conditions by the use of titanocene catalyst in the presence of ^<11>BuMgCl giving rise to 1,4-carbosilylated or 1,4-double silylated 2-butenes. Aryl substituted alkenes also afford 1,2-carbosilylated or 1,2-double silylated products under similar conditions.