An Outlook to Six- and Pseudo Six-component Reactions in Organic Synthesis with a Glance at Some Aspects of Green Chemistry

In this review, we focused on the six- and pseudo-six-component transformations in organic syntheses as a class of important and applicable MCRs. Although the MCRs usage in recent years is enhanced the reports for more than five-component MCRs are still rare. In some cases, these kinds of MCRs are the combination of some tandem named reactions that generated a union MCR. Preparation of multi-functionalized heterocycles, prevention of intermediate separation, reaction progressing in a one-pot continuous manner, elevated total yield, high atom economy, and preparation of potent bioactive multi-cycles hetero-organics via the construction of several new bonds are some highlighted features of MCRs. In this article, we classified the mentioned sixcomponent reactions based on reaction media. Another subdivision is applied based on thermal energy usage or ambient temperature. In fact, two aspects of the green chemistry rules have been discussed.