Tandem Migration–Carboalkoxylation of o-Isocyanophenyl Acetals Leading to Benzoxazoles
摘要:
An efficient approach to benzoxazoles via tandem migration carboalkoxylation of o-isocyanophenyl acetals has been developed. Both a Lewis acid and base are essential for this reaction, and the BF3 center dot OEt2/2,4,6-collidine combination is the best choice for cooperative transformation.
Sunflow: Sunlight Drives Fast and Green Photochemical Flow Reactions in Simple Microcapillary Reactors - Application to Photoredox and H-Atom-Transfer Chemistry
作者:Alexander M. Nauth、Alexander Lipp、Benjamin Lipp、Till Opatz
DOI:10.1002/ejoc.201601394
日期:2017.4.18
“Sunflow“ – The combination of a microcapillary reactor in continuous flow mode with sunlight as the most sustainable energy source imaginable was applied to a range of photoredox and H-atom-transfer reactions making them both fast and green.
“Sunflow”——连续流动模式下的微毛细管反应器与作为可想象的最可持续能源的阳光相结合,应用于一系列光氧化还原和 H 原子转移反应,使其既快速又环保。
Light Induced C–C Coupling of 2-Chlorobenzazoles with Carbamates, Alcohols, and Ethers
作者:Alexander Lipp、Günther Lahm、Till Opatz
DOI:10.1021/acs.joc.6b00715
日期:2016.6.3
A light induced, transition-metal-free C–C coupling reaction of 2-chlorobenzazoles with aliphatic carbamates, alcohols, and ethers is presented. Inexpensive reagents, namely sodium acetate, benzophenone, water, and acetonitrile, are employed in a simple reaction protocol using a cheap and widely available 25 W energy saving UV-A lamp at ambient temperature.
The α-oxyalkylation of aryl chlorides with ethers and alcohols using a small amount of a peroxide was found to be induced by photoirradiation. The reaction proceeds through a homolytic aromatic substitution (HAS) mechanism consisting of addition of an α-oxyalkyl radical to an aryl chloride and elimination of the chlorine atom to give the α-oxyalkylation product, where photoirradiation is considered