Co(III)/Zn(II)-catalyzed dearomatization of indoles and coupling with carbenes from ene-yne ketones via intramolecular cyclopropanation

Visible-light enabled synthesis of cyclopropane-fused indolines via dearomatization of indoles

“…2 In this regard, cyclopropane-fused indolines exist as the key units in many biologically active alkaloids, such as lundurines A–D (Scheme 1a). 3 Typically, strategies for the construction of cyclopropane-fused indolines rely on cyclopropanation of indoles with diazo compounds, 4 cyclopropenes, 5 ene–yne ketones 6 or tosylhydrazones 7 catalyzed by transition-metal complexes or enabled by visible light (Scheme 1b). However, the employment of potentially toxic and explosive carbene precursors might limit their synthetic applications.…”

C(sp2)–H/O–H cross-dehydrogenative coupling of quinoxalin-2(1H)-ones with alcohols under visible-light photoredox catalysis

“…Quinoxalin-2(1H)-ones are prevalent nitrogen-heterocyclic units [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] in a broad range of pharmaceutically and biologically active compounds [19,20]. As a consequence, the development of novel synthetic protocols for the facile diversification of quinoxalin-2(1H)-one has been actively explored over the past few years [21].…”