著者

Takashi Ikawa Hiroaki Tokiwa Shuji Akai

出版者

社団法人 有機合成化学協会

雑誌

有機合成化学協会誌 (ISSN:00379980)

巻号頁・発行日

vol.70, no.11, pp.1123-1133, 2012-11-01 (Released:2012-12-05)

参考文献数

86

被引用文献数

7 17

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The silyl- and boryl-directed regiocontrol of benzyne reactions and their theoretical analyses using density functional theory (DFT) are described herein. The Diels-Alder reactions of both 3-silyl- and 3-borylbenzynes with substituted furans and the [3+2] cycloadditions of 3-silylbenzynes with 1,3-dipoles predominantly produced distal cycloadducts, whereas the [3+2] cycloadditions of the borylbenzynes exclusively produced proximal cycloadducts. Moreover, primary amines selectively underwent nucleophilic addition reactions at the more hindered ortho-position of the silyl group of the benzynes. The origin of these anomalous regiochemistries was theoretically evaluated using the natural bond orbital and reaction pathway analyses including the transition states of these reactions. On the basis of DFT calculations, it is proposed that the reactions of the borylbenzynes were controlled by the electrostatic effect of the boryl group, whereas those of the silylbenzynes were primarily governed by the steric effect of the silyl group.