Tuning rate of the bergman cyclization of benzannelated enediynes with ortho substituents

IV Alabugin, M Manoharan, SV Kovalenko

Index: Alabugin, Igor V.; Manoharan, Mariappan; Kovalenko, Serguei V. Organic Letters, 2002 , vol. 4, # 7 p. 1119 - 1122

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Citation Number: 97

Abstract

The present study was prompted by our experimental finding of an accelerating effect by an electron-donating OMe group at the ortho position. 10 Although the effect is subtle 2,3-diethynylanisole is only two times more reactive than 1,2-diethynylbenzene at 170 °C 11 (Table 2, Supporting Information) the direction of the change is unexpected. The accelerating influence of an electron-donor substituent clearly contradicts with the simple premise of the Koga− ...