Photoinduced 6π-Electrocyclization of 1, 3, 5-hexatriene system containing allomaltol fragment: A convenient approach to polycondensed pyrrole derivatives. (21st May 2022)

• Record Type: Journal Article
• Authors: Komogortsev, Andrey N.; Milyutin, Constantine V.; Lichitsky, Boris V.; Melekhina, Valeriya G.
• Is Part Of: Tetrahedron. Volume 114(2022)
• Publication Date: 2022-05-21
• Subjects: Electrocyclic reactions -- 1, 3, 5-Hexatriene system -- Allomaltol -- Terarylenes -- Photochemistry; Chemistry, Organic -- Periodicals; 547.005
• DOI: 10.1016/j.tet.2022.132780
• Languages: English
• ISSNs: 0040-4020

Abstract

Abstract: An efficient photochemical approach was developed for the synthesis of benzo[ e ]pyrano[3, 2- g ]indoles. The presented method is based on 6π-electrocyclization of terarylenes containing pyrrole and allomaltol fragments. Various options for increasing the regioselectivity of the proposed approach, including both chemical modification of the allomaltol moiety and the use of certain conditions that block side processes were suggested. Advantages of this method are the employment of readily accessible starting materials, operational simplicity and easy isolation of the target products avoiding chromatographic purification. It was demonstrated that the considered photoreaction of allomaltol derivatives can be employed for the photoacid generation. The structure of one of the synthesized photoproducts was established by X-ray diffraction. Graphical abstract: To create your abstract, type over the instructions in the template box below. Fonts or abstract dimensions should not be changed or altered. Image 1 Highlights: 6π-electrocyclization of terarylenes with allomaltol and pyrrole fragments. Efficient photochemical synthesis of benzo[ e ]pyrano[3, 2- g ]indoles. Various options for increasing the regioselectivity of the process were suggested. Considered photoreaction can be employed for the photoacid generation. One of the synthesized photoproducts was established by X-ray diffraction.