118758-47-7Relevant articles and documents
Organocatalytic michael addition of nitro esters to a,β-unsaturated aldehydes: Towards the enantioselective synthesis of trans-3-substituted proline derivatives
Han, Man-Yi,Zhang, Yong,Wang, Huai-Zhen,An, Wan-Kai,Ma, Bao-Chun,Zhang, Yuan,Wang, Wei
, p. 2635 - 2640 (2013/01/15)
A facile five-step strategy has been developed for the enantioselective synthesis of trans-3- substituted proline derivatives with high diasteroselectivity (dr>20:1) and enantioselectivity (up to 97% ee). The key step is the asymmetric organocatalytic Michael addition of nitro esters to a,β-unsaturated aldehydes, which affords the chiral Michael adducts in high yields (up to 96%) and excellent enantioselectivity (up to 99% ee) by using diaryl- ACHTUNGTRENUNGprolinol silyl ether as the organocatalyst.
Highly Diasteroselective Michael-Addition of Lithiated Camphor Imines of Glycine Esters to α,β-Unsaturated Esters. Synthesis of Optically Pure 5-Oxo-2,4-pyrrolidinedicarboxylates of Unnatural Stereochemistry
Kanemasa, Shuji,Tatsukawa, Akira,Wada, Eiji
, p. 2875 - 2883 (2007/10/02)
The lithium enolates of camphor imines of glycine esters underwent highly diastereoselective Michael additions to the α,β-unsaturated esters.The tightly chelated structure of the Z,E enolates and the selective approach of the α,β-unsaturated esters to the
Synthesis of Enantio- and Diastereoiso-merically Pure Substituted Prolines via Condensation of Glycine with Olefins Activated by a Carbonyl Group
Belokon', Yuri N.,Bulychev, Aleksandr G.,Pavlov, Viacheslav A.,Fedorova, Eugenia B.,Tsyryapkin, Vladimir A.,et al.
, p. 2075 - 2084 (2007/10/02)
The glycine fragment in the nickel(II) complex (1) formed from the Schiff's base of glycine and (S)-o-benzophenone (2) undergoes base-catalysed Michael addition to acrylaldehyde, α-methylacrylaldehyde, (E)-crotonaldehyde, (E)-cinnamaldehyde, and methyl vinyl ketone.No products of 1,2-addition were found in the Et3N-catalysed reactions.Addition followed by epimerization of the isomeric complexes proceeds with high diastereoselectivity at Cα (90percent) and Cβ of the corresponding amino acid side chains.After chromatographic separation, the diastereoisomerically pure complexes were decomposed and the resulting dihydropyrrole-2-carboxylic acids reduced with NaBH3CN to give (S)-proline, trans-3-methyl-(S)-proline, trans-5-phenyl-(S)-proline, and a mixture of cis- and trans-5-methyl-(S)-prolines.The chiral auxiliary (2) was recovered in 80-90percent yield.