Abstract
The origin and growth of the chemistry of 1,4-benzodioxins, 1,4-benzoxazines and their 2,3-dihydro derivatives are briefly described. This class of compounds has attracted special attention due to their natural occurrence and important biological activities. The structural scaffolds of these heterocycles serve as building blocks in various useful syntheses. The introduction of palladium-catalyzed reactions has added a new dimension to this field by making the synthesis more convenient and general. The purpose of this account is to facilitate and revitalize interest in this field within the synthetic community.
1 Introduction
2 Naturally Occurring Derivatives
2.1 2,3-Dihydro-1,4-benzodioxin Derivatives
2.2 2,3-Dihydro-1,4-benzoxazine Derivatives
3 Medicinal Importance
3.1 1,4-Benzodioxins and their 2,3-Dihydro Derivatives
3.2 1,4-Benzoxazines and their 2,3-Dihydro Derivatives
4 Synthetic Methods
4.1 1,4-Benzodioxins
4.2 2,3-Dihydro-1,4-benzodioxins
4.3 1,4-Benzoxazines
4.4 2,3-Dihydro-1,4-benzoxazines
4.5 1,4-Benzoxazin-3-ones and Derivatives
4.6 2,3-Dihydro-2-(or 3)-aryl(alkyl)idene-1,4-benzoxazins and Others
5 Synthetic Applications
5.1 1,4-Benzodioxanes
5.2 1,4-Benzoxazines
6. Conclusions
Key words
1,4-benzodioxin - 1,4-benzoxazine - biological significance - natural products - syntheses - palladium catalyst - synthetic intermediates