Catalyst-free and additive-free reactions enabling C–C bond formation: a journey towards a sustainable future

Abstract

This review focuses on the catalyst- and additive-free C–C bond forming reactions reported mostly from the year 2005 to date. C–C bond forming reactions are highly important as large and complex organic molecules can be derived from simpler ones via these reactions. On the other hand, catalyst- and additive-free reactions are economical, environmentally friendly and less sensitive to air/moisture, allow easy separation of products and are operationally simple. Hence, a large number of research articles have been published in this area. Though a few reviews are available on the catalyst-free organic reactions, most of them were published a few years ago. The current review excludes catalysts as well as additives and is specific to only C–C bond formation. Besides many organic name reactions, catalyst/additive-free C–H functionalizations, coupling reactions and UV-visible-light-promoted reactions are also discussed. Undoubtedly, the contents of this review will motivate readers to do more novel work in this area which will accelerate the journey towards a sustainable future.