Visible-light-induced decarboxylative cyclization.

Area of Science:

• Organic Chemistry
• Photochemistry
• Synthetic Methodology

Background:

• Visible light photoredox catalysis offers mild, selective conditions for organic transformations.
• Photoinduced decarboxylative coupling reactions have advanced significantly, utilizing single electron transfer (SET) to generate reactive radicals.
• Carboxylic acids and their derivatives are versatile precursors for radical generation.

Purpose of the Study:

• To review recent progress in visible-light-mediated decarboxylative cyclization of carboxylic acids.
• To highlight the construction of carbo- and heterocycles using these methods.
• To focus on advancements from 2020-2024.

Main Methods:

• Review of literature published between 2020 and 2024.
• Focus on reactions involving visible-light irradiation and decarboxylative coupling.
• Categorization of annulation strategies including organophotocatalysis, metallaphotocatalysis, and photocatalyst-free approaches.

Main Results:

• Demonstration of diverse carboxylic acid derivatives (amino acids, NHPI esters, keto acids, etc.) coupling with various substrates.
• Successful construction of structurally complex carbo- and heterocycles.
• Overview of different photocatalytic systems (e.g., 4CzIPN, g-C3N4, Eosin Y, methylene blue) and photocatalyst-free methods.

Conclusions:

• Visible-light-driven decarboxylative cyclization is a powerful strategy for synthesizing cyclic compounds.
• The field has seen rapid development in methodology, scope, and mechanistic understanding.
• This review provides insights into emerging trends and future directions in this area.