Extended mesoionic systems: synthesis and characterization of monocyclic, polycyclic and macrocyclic pyrimidinium-olate derivatives and their photochemical behavior

被引：11

作者：

Koch, A

Jonas, U

Ritter, H

Spiess, HW

机构：

[1] Max Planck Inst Polymer Res, D-55128 Mainz, Germany

[2] Inst Organ Chem & Macromol Chem, D-40225 Dusseldorf, Germany

来源：

TETRAHEDRON | 2004年 / 60卷 / 44期

关键词：

polycyclic mesoions; pyrimidinium-olates; photocyclization reaction;

D O I：

10.1016/j.tet.2004.08.003

中图分类号：

O62 [有机化学];

学科分类号：

070303 ; 081704 ;

摘要：

Mesoionic pyrimidinium-olate derivatives have been known to undergo photoreactions upon irradiation with UV light to form bis(beta-lactame) structures for about two decades. Here, new mono-, poly- and macrocyclic mesoions were prepared and their photochemical rearrangement behavior was investigated. The synthesized compounds were characterized by NMR, IR, UV/Vis spectroscopy, elemental analysis and mass spectrometry. The extension of the aromatic core leads to a significant red-shift of the absorption maximum from similar to380 to similar to430 nm, indicating a strong electronic coupling of the mesoionic base chromophore with the annellated aromatic subunit. The rigidity of the extended aromatic system prevents polycyclic mesoions from shifting to their bis(beta-lac tame) isomers, while the alkyl bridge of the 16-membered macrocycle in an ansa-mesoion does not inhibit photochemical rearrangement. (C) 2004 Elsevier Ltd. All rights reserved.

引用

页码：10011 / 10018

页数：8

共 15 条

[1]

BONGINI A, 1979, SYNTHESIS-STUTTGART, P618

[2] ELIMINATION-ADDITION MECHANISM FOR BASE-CATALYZED CONVERSION OF S-ALKYLISOTHIOUREAS TO UREAS [J].