Photoredox-Catalyzed Synthesis of C-Benzoselenazolyl/Benzothiazolyl Glycosides from 2-Isocyanoaryl Selenoethers/Thioethers and Glycosyl Bromides

Abstract

Molecules containing heteroatoms, such as Se and S, play an indispensable role in the discovery and design of pharmaceuticals, whereas Se has been less studied. Here, we described a photoredox strategy to synthesize C-benzoselenazolyl (Bs) glycosides from 2-isocyanoaryl selenoethers and glycosyl bromides. This reaction was carried out under mild conditions with high efficiency. C-Benzothiazolyl (Bt) glycosides could also be synthesized from 2-isocyanoaryl thioethers using this strategy. This method can access novel seleno/thiosugars, which will benefit Se/S-containing drug discovery.

Photocatalytic cyclization of 3-(2-isocyanophenyl)quinazolin-4(3H)-ones for the construction of quinoxalino[2,1-b]quinazolinones

“…Bearing a negatively charged carbon and positively charged nitrogen, isocyanides are widely used as radical acceptors in the cascade cyclization reactions to construct valuable and complex heterocyclic structures. 8 For example, the synthesis of phenanthridines, 9 isoquinolines, 10 pyrrolo[1,2- a ]quinoxalines, 11 benzothiazoles, 12 pyridines, 13 and indoles 14 can be achieved via the radical cascade cyclization of isocyanides. The exploration of new skeletons bearing isocyanide as radical acceptors for the construction of novel nitrogen-containing heterocycles is highly anticipated.…”

Preparing glycosyl benzothiazoles from 2-isocyanoaryl thioethers and glycosyl radicals under thermal conditions

“…Moreover, it has been extensively documented that isonitriles 14 can function as radical acceptors for constructing benzothiazole derivatives. 6 b ,20 In this context, we surmise that these reagents could be exceptionally well-suited for the synthesis of glycosyl benzothiazoles through a radical cascade cyclization. Yet, the reactivity of glycosyl radicals with isonitriles and the subsequent cleavage of the S–Me bond play crucial roles in the success of this conceptualization.…”