From Conventional Reaction Conditions to Microwave-Assisted Catalytic Transformations of Various Substrates. State of the Art in 2012 (Part A: General)

Abstract

Microwave irradiation as a modern approach to various organic transformations, specially in combination with the use of homogeneous or heterogeneous catalysts, is a well-established strategy for the preparation of a range of important compounds. However, due to the recent enormous expansion of the field of modern, catalytic transformations of different types, we present the title subject in the form of two reviews (Part A: General and Part B: Catalysis). In Part A, we provided a general overview of the underlying principles of the application of microwaves in organic synthesis. Furthermore, we presented a selection of examples of catalyst-free applications of principles of the green chemistry, such as use of water as the solvent, application of neat reaction conditions and reactions taking place on solid supports. In Part B [1], we described the reactions carried out using microwaves in the combination with various types of catalysts (transition-metal-catalyzed transformation, organocatalysis, phase-transfer catalysis, the use of inorganic catalysts and ionic liquids, etc.). In addition, we looked at the syntheses and transformations of different organic targets with the emphasis on heterocycles, especially on those containing a 2H-pyran-2-one moiety in their structure. A particular interest is also dedicated to the environmentally benign reaction conditions.