189756-71-6Relevant academic research and scientific papers
A novel approach towards 2,3,5-trisubstituted thiophenes via tandem Michael addition/intramolecular Knoevenagel condensation
Obrecht,Gerber,Sprenger,Masquelin
, p. 531 - 537 (1997)
Starting from the easily available, highly functionalized acetylenic ketones 4a-i, novel 2,3,5-trisubstituted thiophenes 1a-i were synthesized in good yields using a tandem Michael-addition/intramolecular Knoevenagel-condensation strategy, featuring Cs2CO3/MgSO4 (1:2) as an efficient base to effect the cyclization. Subsequent simple one-step transformations yielded 2,3-disubstituted thiophene-5-carbaldehydes 7a-c, carboxylic-acid derivatives 8, 9, and 11, and alcohol 10. These molecules constitute interesting novel thiophene-containing building blocks, useful for the preparation of low-molecular-weight compound libraries by combinatorial and parallel-chemistry techniques.
