Synthesis of 4-Trifluoromethylpyridines by [5+1] Cyclization of 3-Hydroxy-pent-4-yn-1-ones with Urea
作者:Viktor O. Iaroshenko、Dmytro Ostrovskyi、Khurshid Ayub、Anke Spannenberg、Peter Langer
DOI:10.1002/adsc.201200687
日期:——
alkynylation reactions which are not possible for alkyl- or aryl-substituted derivatives. The products can be easily transformed into 2,6-diaryl-4-trifluoromethylpyridines by acid-mediated [5+1] cyclization with urea. The reaction was thoroughly optimized by variation of the conditions and the scope was studied in detail. The products are not readily available by other methods. A plausible mechanism was