β-Functionalization of Carboxylic Anhydrides with β-Alkyl Substituents through Carbene Organocatalysis
作者:Zhichao Jin、Shaojin Chen、Yuhuang Wang、Pengcheng Zheng、Song Yang、Yonggui Robin Chi
DOI:10.1002/anie.201408604
日期:2014.12.1
The first NHC‐catalyzed functionalization of carboxylicanhydrides is described. In this reaction, the β carbon behaves as a nucleophilic carbon and undergoes asymmetric reactions with electrophiles. Anhydrides with challenging β‐alkyl substituents work effectively.
Asymmetric epoxidation of 2-arylidene-1,3-diketones: facile access to synthetically useful epoxides
作者:Alessio Russo、Alessandra Lattanzi
DOI:10.1039/c002587a
日期:——
enantioselective epoxidation reaction of acyclic and cyclic 2-arylidene-1,3-diketones is reported. Easily accessible or commercially available α,α-diaryl prolinols as the organocatalysts in the presence of tert-butyl hydroperoxide (TBHP) provide the corresponding epoxides in high to excellent yield (up to 99%) and up to 85% ee (ee >90% after crystallisation). These epoxides are pharmaceutically important
Preparation of Tetrasubstituted Furans via Intramolecular Wittig Reactions with Phosphorus Ylides as Intermediates
作者:Tzu-Ting Kao、Siang-en Syu、Yi-Wun Jhang、Wenwei Lin
DOI:10.1021/ol101080q
日期:2010.7.2
functional furans can be efficiently generated in one step at room temperature within 10 min to 21 h in moderate to high yields (60−99%). The reaction was proposed to proceed via intramolecular Wittig-type reactions, using phosphorus ylides as intermediates.
Catalytic Asymmetric Michael Addition/Cyclization of Isothiocyanato Oxindoles: Highly Efficient and Versatile Approach for the Synthesis of 3,2′-Pyrrolidinyl Mono- and Bi-spirooxindole Frameworks
作者:Yi-Ming Cao、Fang-Fang Shen、Fu-Ting Zhang、Rui Wang
DOI:10.1002/chem.201204114
日期:2013.1.21
A‐spiro‐ing to greatness: The catalytic asymmetric Michael addition/cyclization of isothiocyanato oxindoles has been realized. This versatile approach provides an easy and highly efficient way to access not only the enantioselective synthesis of 3,2′‐pyrrolidinyl spirooxindole frameworks, but also the construction of enatiomerically enriched bi‐spirooxindoles containingthreecontiguous stereocenters
Regioselective
<scp>aza‐Michael</scp>
additions of
<scp>2‐arylidene</scp>
‐1,3‐diphenylpropan‐1,3‐diones with isatins: Synthesis of
<scp>N‐diketone</scp>
‐functionalized isatins
作者:Ya Cheng、Zheng Li
DOI:10.1002/jhet.4075
日期:2020.10
The efficient aza‐Michaeladditions of isatins to 2‐arylidene‐1,3‐diphenylpropan‐1,3‐diones at room temperature in the presence of cesium carbonate are described. The salient features of this protocol are no transition‐metal catalysts, mild conditions, high regioselectivity, high atom economy, satisfactory yield and simple work‐up procedures.