Efficient one-pot synthesis of highly substituted thiophene library from 1,3-dicarbonyl compounds.
A facile and efficient one-pot synthesis of highly substituted thiophenes has been developed and employed for the preparation of a small focused library. Treatment of 1,3-dicarbonyl compounds 1 with CS2 in the presence of K2CO3 in DMF at room temperature, followed by stepwise addition of alkyl bromides 2 and methylene active bromides 3, provided via intramolecular cyclization 2,3,4,5-tetrasubstituted thiophenes 4 in yields of 77-94%. This protocol, combining construction and modification of the thiophene ring, increases the structural diversity of final products from readily available materials. A mechanism for the one-pot synthesis of thiophenes of type 4 has been proposed. A small focused library of thiophenes is prepared using the sequential addition of reagents to achieve unique substitution in the 2 and 5 position of the thiophene ring.
Wang
Yan
Y
Department of Chemistry, Northeast Normal University, Changchun 130024, P. R. China.
Huang
Jie
J
Chai
Yanyan
Y
Liu
Qun
Q
Liang
Yongjiu
Y
Dong
Dewen
D
D020650:Combinatorial Chemistry Techniques / Q000379:methods*; D015394:Molecular Structure; D013876:Thiophenes / Q000138:chemical synthesis* / Q000737:chemistry
D013876:Thiophenes