An unprecedented enantioselectiveconjugateaddition reaction of sodium bisulfite to various nitrostyrenes occurred upon the influence of a bifunctional amino-thiourea organocatalyst; a strategy that opens a straightforward route to unprotected chiral taurine derivatives thanks to the reduction of the obtained β-nitroethanesulfonic acids into the corresponding amino derivatives.
Enantioselective Addition of Thioacetic Acid to Nitroalkenes via <i>N</i>-Sulfinyl Urea Organocatalysis
作者:Kyle L. Kimmel、MaryAnn T. Robak、Jonathan A. Ellman
DOI:10.1021/ja903351a
日期:2009.7.1
The highly enantioselectiveaddition of thioaceticacid to nitroalkenes using a new sulfinyl urea organocatalyst is described. The addition of thioaceticacid proceeds in high yields and enantioselectivities for a variety of aromatic and aliphatic nitroalkene substrates. This new method is useful for preparing chiral 1,2-aminothiol derivatives, as demonstrated by the first enantioselective synthesis
Organocatalytic asymmetric conjugate addition of thioacetic acid to β-nitrostyrenes
作者:Hao Li、Jian Wang、Liansuo Zu、Wei Wang
DOI:10.1016/j.tetlet.2006.02.036
日期:2006.4
A method for organocatalytic, enantioselective Michael addition reactions of thioaceticacid with a range of trans-β-nitrostyrenes has been developed. The processes, promoted by the chiral amine thiourea organocatalyst, take place in high yields with up to 70% ee.
Enantioselective Sulfur-<i>Michael</i>Addition of Thioacetic Acid to Nitroalkenes Catalyzed by Bifunctional Amine-Thiourea Catalysts
作者:Renchao Wang、Jiaxi Xu
DOI:10.1002/hlca.201400125
日期:2014.12
An enantioselectiveMichaeladdition of thioacetic acid (AcSH) to nitroalkenes, catalyzed by a leucine‐derived bifunctional aminethiourea, was developed with high yields and moderate enantioselectivities. The thiourea‐ammonium salt formed in the reaction is identified as the active catalyst, and the multiple H‐bonding system is responsible for the stereocontrol. The resulting thioester products are
Squaramide-catalysed enantio- and diastereoselective sulfa-Michael addition of thioacetic acid to α,β-disubstituted nitroalkenes
作者:Wen Yang、Da-Ming Du
DOI:10.1039/c2ob26068a
日期:——
A highly enantio- and diastereoselective sulfa-Michael addition of thioacetic acid to α,β-disubstituted nitroalkenes catalysed by a chiral squaramide organocatalyst has been described. This organocatalytic reaction at an extremely low catalyst loading (0.2 mol%) furnished synthetically useful β-nitro sulfides in excellent yields with good diastereoselectivities and high enantioselectivities (up to 94â:â6 dr, 95% ee). In addition, the catalytic reaction can be performed on a 10 gram scale, and facile transformation into taurine derivative is also presented.