Fluoroboric acid adsorbed on silica-gel (HBF4–SiO2) as a new, highly efficient and reusable heterogeneous catalyst for thia-Michael addition to α,β-unsaturated carbonyl compounds
作者:Gaurav Sharma、Raj Kumar、Asit K. Chakraborti
DOI:10.1016/j.tetlet.2008.04.144
日期:2008.6
found to be a new and highly efficient heterogeneous catalyst for thia-Michael addition to α,β-unsaturated carbonyl compounds under solvent-free conditions. In the case of 1,3-diaryl-2-propenones, the reactions are best carried out in MeOH. The rate of thia-Michael addition was dependent on the steric hindrance at the β-carbon of the α,β-unsaturated carbonyl substrate as well as surrounding the thiol
已经发现,吸附在硅胶上的氟硼酸(HBF 4 -SiO 2)是一种新型的高效多相催化剂,可在无溶剂条件下将硫杂-迈克尔加成到α,β-不饱和羰基化合物上。在1,3-二芳基-2-丙烯酮的情况下,反应最好在MeOH中进行。thia-Michael加成的速率取决于α,β-不饱和羰基底物的β-碳以及周围硫醇部分的位阻,并被用于在两个烯酮之间的分子间竞争中选择性的thia-Michael加成。常见的硫醇和两个芳基/烷基硫醇之间的一个常见的烯酮 该方法可用于一锅合成2,3-二氢-1,5-苯并噻氮ze类化合物。