Catalytic Synthesis of 2H-Chromenes

Abstract

2H-Chromenes (2H-1-benzopyran derivatives) display a broad spectrum of biological activities. The 2H-chromene substructure is an important structural motif present in a variety of medicines, natural products, and materials showing unique photophysical properties. Hence, the structural importance of the benzopyran moiety has elicited a great deal of interest in the field of organic synthesis and chemical biology to develop new and improved synthesis of these molecular skeletons. This review gives an up-to-date overview of different catalytic methodologies developed for the synthesis of 2H-chromenes and is structured around the three main approaches applied in catalytic 2H-chromene synthesis: (I) catalysis with (transition) metals, (II) metal-free Brønsted and Lewis acid/base catalysis, which includes examples of nonenantioselective organocatalysis, and (III) enantioselective organo-catalysis. The section in which the metal-catalyzed reactions are discussed describes different ring-closing strategies based on (transition) metal catalysis, including a few enantioselective approaches. For most of these reactions, plausible mechanisms are delineated. Moreover, synthesis of some natural products and medicinally important drugs are included. Specific advantages and disadvantages of the several synthetic methodologies are discussed. The review focuses on catalytic 2H-chromene synthesis. However, for a complete overview, synthetic routes involving some stoichiometric steps and reactions producing ring-scaffolds that are closely related to 2H-chromenes are also included.

Selenocystine Peptides Performance in 5‐endo‐dig Reactions

“…We chose to utilize anisole‐containing aryldiyne 7 for the construction of indeno[1,2‐ c ]chromene skeleton. Chromene moiety is often found in biologically active natural products, furthermore, compounds containing indeno[1,2‐ c ]chromene core show high potential for use in dye‐sensitized photovoltaic cells , . Notably, only few methods exist for the construction of indeno[1,2‐ c ]chromene moiety.…”

An easy synthesis of diversely functionalized 2H-chromenes and amido amines by an enol-Ugi reaction

“…1,2 In addition, many 2H-chromenes have utility as photochromic materials [3][4][5][6] and as intermediates in the synthesis of more complex polycyclic heterocycles. [7][8][9][10][11] These important applications have stimulated the development of diverse synthetic approaches to 2H-chromenes; however, new efficient strategies leading to novel substitution patterns are still required.…”

Highly Efficient Synthesis of New 2H-Chromene Dyes using Cu-SBA-15

“…2 H-chromenes are ver y impor tant heterocyclic compounds which have shown biological activities [1][2][3][4] , some medical properties such as antihypertensive 5 and cardio protectors as well as hypoglycemic agents 6,7 . Some of them are insecticide compounds 8 .…”