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Efficient One‐Pot Access to 2,9‐Dihydrothiopyrano[2,3‐ b ]indole Scaffolds Showing Large Stokes Shifts
Author(s) -
Singh Shivendra,
Samanta Sampak
Publication year - 2015
Publication title -
chinese journal of chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.28
H-Index - 41
eISSN - 1614-7065
pISSN - 1001-604X
DOI - 10.1002/cjoc.201500572
Subject(s) - chemistry , dabco , indole test , substrate (aquarium) , aryl , tandem , atom economy , medicinal chemistry , combinatorial chemistry , reaction conditions , nitro , organic chemistry , octane , catalysis , oceanography , alkyl , materials science , composite material , geology
A simple, mild and efficient one‐pot approach for the construction of 2‐aryl‐3‐nitro‐2,9‐dihydrothiopyrano[2,3‐ b ]indole derivatives has been realized in CH 2 Cl 2 medium at ambient temperature via three‐component tandem reaction of N ‐protected‐2‐chloro‐3‐formylindoles, sodium hydrosulfide and β ‐substituted nitroolefins/ δ ‐substituted nitrodienes using DABCO (10 mol%) as an organocatalyst, followed by dehydration in the presence of activated molecular sieves (4 Å). The significant advantages of this protocol are simple operation, shorter reaction time, high atom economy, good to high yields (73% –89%) and wider substrate scope. In addition, all the synthesized compounds have shown the large positive Stokes shift values (5632–6081 cm −1 ).