PERISELECTIVITY IN THE REACTIONS OF CYCLOPENTADIENONES WITH 8-ARYL-8-AZAHEPTAFULVENES

被引：11

作者：

GAMBA, A

GANDOLFI, R

OBERTI, R

SARDONE, N

机构：

[1] UNIV PAVIA,DIPARTIMENTO CHIM ORGAN,VIA TARAMELLI 10,I-27100 PAVIA,ITALY

[2] CNR,CTR STUDIO CRISTALLOCHIM & CRISTALLOG,I-27100 PAVIA,ITALY

来源：

TETRAHEDRON | 1993年 / 49卷 / 28期

关键词：

PERISELECTIVITY; CYCLOADDITIONS; DIENES; TRIENES;

D O I：

10.1016/S0040-4020(01)87969-2

中图分类号：

O62 [有机化学];

学科分类号：

070303 ; 081704 ;

摘要：

8-Aryl-8-azaheptafulvenes 2 reacted smoothly with 2,5-dimethyl-3,4-diphenylcyclopentadienone (1a) to give exo [8+4] adducts, i.e. 4, as the dominant adducts along with minor amounts of endo [4+2] adducts, i.e. 7 and 8, and trace amounts of [8+2] adducts, i.e. 6. Passing from 2,5-dimethyl to 2,5-dimethoxycarbonyl-3,4-diphenylcyclopentadienone (1c) brought about an increase in reaction rate without any relevant change in selectivity. Structures of the exo [6+4] adducts 4 rest firmly on spectroscopic data and chemical behavior. Upon heating the [6+4] adducts 4 underwent a 13,31 aza-Cope rearrangement followed by [1,5-H] sigmatropic shifts to afford the [8+2] adducts 6. Mechanisms of formation of all the adducts are discussed We conclude that only concerted cycloadditions are at work in the reactions of azaheptafulvenes with cyclopentadienones

引用

页码：6331 / 6348

页数：18

共 43 条

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