Employing Visible-Light Photoredox Catalysis in Multicomponent–Multicatalyst Reactions: One-Pot Synthesis of Spiroquinazolin-2-(thi)ones

Abstract

The multicomponent−multicatalyst reaction ((MC) 2 R) and visible-light catalysis have emerged as green and powerful strategies for achieving ideal syntheses. Here, we report the first example of a visible-light-induced approach toward spiroquinazolin(thi)ones. This (MC) 2 R features an eco-friendly energy source and solvent, metal-free catalysts, step-and atomeconomy, a relay catalysis strategy, air as green oxidant, mild conditions, and easily accessible starting materials.

Study and application of graphene oxide in the synthesis of 2,3-disubstituted quinolinesviaa Povarov multicomponent reaction and subsequent oxidation

“…[6][7][8][9] Recently, the range of possible multicomponent reactions has been greatly expanded by using photocatalysis and electrocatalysis. [10][11][12][13] When MCRs are included in a one-pot multistep process the advantages multiply, saving time and energy (step and operational efficiency) and reducing waste, therefore approaching the concept of an ideal eco-friendly synthesis. 14,15 Recently carbon nanomaterials, with particular reference to graphene oxide (GO), have shown to exhibit interesting catalytic activity in organic transformations, [16][17][18] such as C-C bond formation, 19,20 C-N and C-O oxidation, [21][22][23] thiol oxidation 24 and different MCRs.…”

“…6–9 Recently, the range of possible multicomponent reactions has been greatly expanded by using photocatalysis and electrocatalysis. 10–13 When MCRs are included in a one-pot multistep process the advantages multiply, saving time and energy (step and operational efficiency) and reducing waste, therefore approaching the concept of an ideal eco-friendly synthesis. 14,15…”

I2-mediated coupling of quinazolinone enamines with 2-aminopyridines: a new strategy to access spiroquinazolinones

“…In view of their interesting properties, great progress has been made in the architecture of the spirocyclic quinazolinone frameworks. 24 We recently devoted efforts to the construction of spiroquinazolinones from quinazolinone enamines by harnessing the intrinsic reactivity of these enamines with 2-aminobenzaldehydes, 25 2-hydroxybenzyl acetates, 26 N -methylanilines 27 and N -phenylglycines 28 (Scheme 1b). In order to expand the scope of reacting partners with enamines and inspired by the advantages of the umpolung strategy, in the current work we developed an I 2 -mediated umpolung at the beta-position of quinazolinone enamines with 2-aminopyridines for the synthesis of spiroquinazolinones (Scheme 1c).…”

Construction of Quinazolin(thi)ones by Brønsted Acid/Visible-Light Photoredox Relay Catalysis

“…As a consequence, there is continued effort on developing eco-friendly strategies to access quinazoline-2,4-diones in a metal-free and mild approach. Inspired by the advantages of photoredox catalysis [13] and in continuation to our own efforts on the construction of quinazolin(thi)one derivatives, [14] herein, we present a visible-light and Brønsted acid relay catalyzed construction of skeleton of quinazoline-2,4-dione and quinazoline-2-thione-4-one from readily available 2-aminoacetophenones and iso(thio)cyanates (Scheme 1, e).…”