Squaramide-catalysed enantioselective Michael addition of pyrazolin-5-ones to nitroalkenes
An efficient chiral squaramide-catalysed enantioselective Michael addition of pyrazolin-5-ones to nitroalkenes has been developed. This reaction afforded the chiral pyrazol-3-ol derivatives in high to excellent yields (up to >99%) with high enantioselecti