**Abstract**

The chemistry of aldehydes and resembling chromophores portraits a natural tendency to undergo chemical reactions through nucleophilic reagents, owing to the polarization arising from the electronegativity of oxygen atom, and they also can enolize as a result of the acidic nature of the α-hydrogen of the carbonyl functional group; thereby the CdC bond forming reactions can be attained either intra- or intermolecularly. Carbonyl addition reactions, enolate chemistry coupled with their capability to undergo [2+2] cycloaddition reactions, and the chemistry of carbonyl compounds are being mind-numbingly exploited in the design and process development of industrially, commercially, pharmacologically, and biologically valueadded compounds. Ultimately abundant name reactions were registered, and many novel reactions endlessly appear; of late, prodigious development has been reported under the heading of visible-light photocatalysis (VLPC). Fascinatingly, VLPC has opened a new domain in the synthetic organic chemistry, and this domain paves the way to access broad spectrum of organic compounds with the ease of operations. In this chapter the chemistry of carbonyls by VPLC is briefly presented, which is comprising of not only functional group transformations but also asymmetric syntheses of complex organic compounds.

**Keywords:** aldehydes, VLPC, photosensitizers, asymmetric alkylation, enamines
