Visible light-mediated applications of methylene blue in organic synthesis

Methylene blue is a versatile organic dye, which possesses adequate potential to be used in photochemical reactions. This readily available dye utilizes visible light as a source of renewable energy to develop suitable catalytic routes involving both single-electron transfer (SET) and energy transfer (EnT) pathways. In this review, we have summarized some physiochemical properties of methylene blue for better understanding of the functioning of the dye and its application in the construction of C-C, C-heteroatom, and heteroatom-heteroatom bonds.