Organocatalytic Synthesis of Heterocycles: A Brief Overview Covering Recent Aspects

The use of small organic molecules as organocatalysts in organic synthesis has been intensely studied over the past decade. In this emerging field, considerable studies have led to the introduction of various efficient organocatalyzed synthetic methods of carbon-carbon and carbon- heteroatom bond formations. The use of these organocatalysts also showed environmentally benign reaction conditions compared to the metal-catalyzed transformations. In this review, we paid special attention to the most recent organocatalytic protocols reported for the synthesis of heterocycles. The studies have been outlined, depending on the organocatalysts used as: (i) nitrogen-based molecules as organocatalyst, (ii) NHCs as organocatalyst, and (iii) phosphorus-based molecules as organocatalysts. The discussion intends to reveal the scope as well as the vitality of organocatalysis in the area of heterocycle synthesis.