Substituent Effect on Reactivity of Triplet Excited State of 2,3-Diazabicyclo[2.2.1]hept-2-enes, DBH Derivatives: α C-N Bond Cleavage versus β C-C Bond Cleavage

被引：7

作者：

Abe, Manabu ^{[1
,3
,4
]}

Watanabe, Shinji ^{[1
]}

Tamura, Hiroshi ^{[1
]}

Boinapally, Srikanth ^{[1
,4
]}

Kanahara, Kousei ^{[1
]}

Fujiwara, Yoshihisa ^{[2
]}

机构：

[1] Hiroshima Univ, Grad Sch Sci, Dept Chem, Higashihiroshima, Hiroshima 7398526, Japan

[2] Hiroshima Univ, Dept Math & Life Sci, Higashihiroshima, Hiroshima 7398526, Japan

[3] Inst Mol Sci, Okazaki, Aichi 4448787, Japan

[4] JST, CREST, Chiyoda Ku, Tokyo 1020076, Japan

来源：

JOURNAL OF ORGANIC CHEMISTRY | 2013年 / 78卷 / 05期

关键词：

CORRELATED MOLECULAR CALCULATIONS; COUPLED-CLUSTER SINGLES; GAUSSIAN-BASIS SETS; AB-INITIO; THERMAL DENITROGENATION; PHOTOCHEMISTRY; DIRADICALS; AZOALKANES; MECHANISM; MODEL;

D O I：

10.1021/jo3019472

中图分类号：

O62 [有机化学];

学科分类号：

070303 ; 081704 ;

摘要：

The photoreaction of a series of 2,3-diazabicyclo[2.2.1]hept-2-ene (DBH) derivatives, in which various substituents (X) were introduced at the methano bridge carbon of C(7), was investigated under direct (>290 nm) and triplet-sensitized (Ph2CO, >370 nm) irradiation conditions of the azo chromophore (-C-beta-C-alpha-N=N-C-alpha-C-beta-). The azo compounds offered a unique opportunity to see the substituent X effect at the remote position of the azo chromophore on the reactivity of the triplet excited state of bicyclic azoalkanes. The present study led to the first observation of the unusual C-alpha-C-beta bond cleavage reaction without the ring stiffness, that is, the structural rigidity, in the triplet state of the cyclic azoalkanes. The stereoelectronic effects were found to play an important role in lowering the activation energy of the C-alpha-C-beta bond cleavage reaction. NBO analyses at the M06-2X/cc-PVDZ level of theory confirmed the stereoelectronic effect.

引用

页码：1940 / 1948

页数：9

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