Potassium Acetate-Catalyzed Double Decarboxylative Transannulation To Access Highly Functionalized Pyrroles
作者:Jun-Kuan Li、Biying Zhou、Yu-Chen Tian、Chunman Jia、Xiao-Song Xue、Fa-Guang Zhang、Jun-An Ma
DOI:10.1021/acs.orglett.0c03621
日期:2020.12.18
remodeling by utilizing CO2 moiety as tracelessactivating and directinggroups in both reaction partners. The synthetic value is evidenced by the rapid preparation of a broad spectrum of highly functionalized 3-carbamoyl-4-aryl pyrroles in good to excellent yields with exclusive regio-control, including the important Atorvastatin core.
Enantioselective Organocatalytic Addition of Oxazolones to 1,1-Bis(phenylsulfonyl)ethylene: A Convenient Asymmetric Synthesis of Quaternary α-Amino Acids
作者:Andrea-Nekane R. Alba、Xavier Companyó、Guillem Valero、Albert Moyano、Ramon Rios
DOI:10.1002/chem.200903025
日期:2010.5.10
A new, easy, and highlyenantioselective method for the synthesis of quaternary α‐alkyl‐α‐aminoacids based on organocatalysis is reported. The addition of oxazolones to 1,1‐bis(phenylsulfonyl)ethylene is efficiently catalyzed by simple chiral bases or thioureas. The reaction affords α,α‐disubstituted α‐aminoacid derivatives with complete C4 regioselectivity and with excellent yields and enantioselectivities
Enantioselective Organocatalytic Addition of Azlactones to Maleimides: A Highly Stereocontrolled Entry to 2,2-Disubstituted-2H-oxazol-5-ones
作者:Andrea-Nekane R. Alba、Guillem Valero、Teresa Calbet、Mercé Font-Bardía、Albert Moyano、Ramon Rios
DOI:10.1002/chem.201000239
日期:2010.8.23
The first highly diastereo‐ and enantioselectiveorganocatalytic synthesis of 2,2‐disubstituted‐2H‐oxazol‐5‐ones is described. The addition of oxazolones to maleimides is promoted by bifunctional thiourea catalysts, which afford the corresponding 2,2‐disubstituted‐2H‐oxazol‐5‐ones with total regio‐ and stereocontrol.
Asymmetric organocatalytic Michael addition of azlactones to cis-1,2-bis(phenylsulfonyl)ethene. A simple entry to quaternary α-amino acids
作者:Natalia Bravo、Andrea-Nekane R. Alba、Guillem Valero、Xavier Companyó、Albert Moyano、Ramon Rios
DOI:10.1039/c0nj00321b
日期:——
Azlactones react with 1,2-bis(phenylsulfonyl)ethene under catalysis by simple chiral thioureas, affording α,α-disubstituted α-amino acid derivatives in good yields and in moderate to good enantioselectivities.
Asymmetric Aza-Mannich Addition of Oxazolones to <i>N</i>-Tosyl Aldimines: Synthesis of Chiral α-Disubstituted α,β-Diamino Acids
作者:Xiaodong Liu、Leijiao Deng、Xianxing Jiang、Wenjin Yan、Chunliang Liu、Rui Wang
DOI:10.1021/ol902916s
日期:2010.2.19
readily prepared cinchona alkaloid ligand and affords a series of valuable α-disubstituted α,β-diamino acid derivatives with excellent enantioselectivities (up to 97% ee) and diastereoselectivities (up to >30:1 dr). The adducts can be transformed into the corresponding protected chiral α-disubstituted α,β-diamino acids by a one-pot hydrolyzed reaction smoothly.