Enantioselective Synthesis of β-(3-Hydroxypyrazol-1-yl) Ketones Using an Organocatalyzed Michael Addition Reaction
作者:Sanjib Gogoi、Cong-Gui Zhao、Derong Ding
DOI:10.1021/ol900538q
日期:2009.6.4
β-(3-Hydroxypyrazol-1-yl) ketones have been prepared in high yields and excellent enantioselectivities (94−98% ee) via a Michaeladdition reaction between 2-pyrazolin-5-ones and aliphatic acyclic α,β-unsaturated ketones using 9-epi-9-amino-9-deoxyquinine as the catalyst. These results account for the first example of an aza-Michael addition of the ambident 2-pyrazolin-5-one anion to a Michael acceptor.