C3-Symmetric cinchonine-squaramide as a recyclable efficient organocatalyst for tandem Michael addition–cyclisation of malononitrile and nitrovinylphenols. Issue 14 (15th August 2016)

• Record Type: Journal Article
• Authors: Lv, Wenxing; Guo, Chao; Dong, Ze; Tang, Shi; Liu, Bin; Dong, Chune
• Is Part Of: Tetrahedron, asymmetry. Volume 27:Issue 14/15(2016)
• Page Start: 670
• Page End: 674
• Publication Date: 2016-08-15
• Subjects: Asymmetry (Chemistry) -- Periodicals; 547.005
• DOI: 10.1016/j.tetasy.2016.05.011
• Languages: English
• ISSNs: 0957-4166

Abstract

Graphical abstract: Abstract: The tandem enantioselective Michael addition/cyclisation reaction of malononitrile and nitrovinylphenols was catalysed by a recoverable C 3 -symmetric cinchonine-squaramide organocatalyst 1a to afford the 2-amino-4 H -chromene-3-carbonitrile derivatives in excellent yields (up to 95%) and with excellent enantioselectivities (up to 98% ee) under mild reaction conditions. Furthermore, this catalyst can be easily recovered four times without loss in activity or enantioselectivity.