A visible-light RuII photoredox Meerwein synthesis of isochromanones and isochromenones is described starting from diazonium salts of differently substituted anthranilic acids and various alkenes. This approach has allowed the reliable and efficient preparation of structures found in many biologically active molecules or used in materials chemistry.
We report here the intermolecular metal-free addition reaction of functionalized benzylhalides to aldehydes using a super electron donor (SED). The metal-free and mild conditions allowed the formation of 3,4-dihydroisocoumarins and 1,2-diarylethanols with unprecedented functional group tolerance.
Addition of Benzyl Halides to Aldehydes and Imines Using Photoactivated TDAE: Access to 3,4-Dihydroisocoumarins, 1,2-Diarylethanols, and 1,2-Diarylcarbamates under Metal-Free Conditions
We describe herein the intermolecular addition reaction of benzylhalides to aldehydes and imines using photoactivated tetrakis(dimethylamino)ethylene (TDAE) as superphotoreductant. 3,4-Dihydroisocoumarins, 1,2-diarylethanols, and 1,2-diarylcarbamates were obtained with good functional group tolerance using simple, mild, and metal-free conditions.
The selective oxidation of the two different benzylethereal position of 3-arylisochromans by dimethyldioxirane as a function of different substituents on the aromatic rings was studied. The easy oxidation of these compounds was exploited for a new easy access to substituted 3-arylisocoumarins. (C) 1999 Elsevier Science Ltd. All rights reserved.