A New Approach to<i>β</i>-Fluoropyrroles Based on the Michael Addition of Isocyanomethylide Anions to<i>α</i>-Fluoroalkenyl Sulfones and Sulfoxides
作者:Hidemitsu Uno、Katsuji Sakamoto、Takashi Tominaga、Noboru Ono
DOI:10.1246/bcsj.67.1441
日期:1994.5
The reactions of 2-aryl-1-fluorovinyl phenyl sulfones with carbanions derived from isocyanoacetates gave mixtures of 3-aryl-4-fluoro-2-pyrrolecarboxylates and 3-aryl-4-fluoro-4-phenylsulfonyl-2-isocyanobutanoates, simple Michael addition products, in variable ratios depending upon the conditions employed. On the other hand, the reaction of 1-fluoro-1-propenyl phenyl sulfone afforded mainly the simple Michael addition products in moderate yields as well as a small amount of 4-phenylsulfonyl-3-methyl-2-pyrrolecarboxylates and a trace amount of 4-fluoro-3-methyl-2-pyrrolecarboxylates. 1-Fluoropropenyl phenyl sulfoxide underwent mainly the simple Michael addition to give butenoates and a small amount of 4-fluoro-2-pyrrolecarboxylates.
2-芳基-1-氟乙烯基苯砜与衍生自异氰乙酸酯的碳负离子的反应得到3-芳基-4-氟-2-吡咯羧酸酯和3-芳基-4-氟-4-苯磺酰基-2-异氰基丁酸酯的混合物,简单迈克尔加成产物,其比例取决于所采用的条件。另一方面,1-氟-1-丙烯基苯砜的反应主要以中等产率提供简单的迈克尔加成产物以及少量的4-苯磺酰基-3-甲基-2-吡咯甲酸酯和痕量的4-氟-3-甲基-2-吡咯甲酸酯。 1-氟丙烯基苯基亚砜主要发生简单的迈克尔加成反应,得到丁烯酸酯和少量的4-氟-2-吡咯甲酸酯。