Photochemical strategies for C–N bond formation via metal catalyst-free (hetero) aryl C(sp²)–H functionalization

Abstract

The development of efficient and mild methods to assemble C–N bonds represents an important and appealing goal in modern synthetic chemistry.

Metal-Catalyst-Free Radical Cyclization of 1,6-Enynes for the Selective and Switchable Synthesis of Lactams in Water

“…The commonly used organic solvents are generally volatile and toxic, so it is a sustainable choice to find environmentally friendly media as an alternative. − As the greenest and safest solvent in nature, water has drawn the attention of chemists due to its excellent biocompatibility, nonflammability, and nontoxicity. − Hence, it is of great significance to exploit organic reactions in aqueous media. In addition, the development of the metal-catalyst-free method is also booming due to its low toxicity, long service life, and simple postprocessing. − Inspired by these advances and as a continuation of our efforts in radical cyclization of unsaturated hydrocarbons, − we present a sustainable and switchable radical cyclization of 1, n -enynes with sulfonyl hydrazines in aqueous media without a metal catalyst to form five-membered cyclic lactams, five-membered cyclic lactams containing C–I bond, and six-membered cyclic lactams (Scheme -2). These protocols have the following prominent advantages: (1) water as the solvent; (2) metal-catalyst-free; (3) high selectivity and controllability; and (4) preparation of diversified products from the same substrate.…”

Mono/Dual Amination of Phenols with Amines in Water

“…The rapid construction of aromatic amines in a green manner is an important research topic in organic and medicinal chemistry. C–N bond formation is among the most efficient strategies for constructing aryl amines . Most C–N bond reactions are examples of Buchwald–Hartwig coupling or Ullmann-type aminations, wherein aryl halides are frequently utilized as electrophiles to couple with amines (Scheme a) .…”

Monte Carlo Analysis-Based CapEx Uncertainty Estimation of New Technologies: The Case of Photochemical Lamps

“…Similar to more established process technology trends such as continuous manufacturing − or process analytical technology, the photochemical − and electrochemical reaction technologies receive significant attention from both the academic and industrial communities …”