of new chiralauxiliaries, 7-alkyl substituted cis-1-amino-2-indanol derivatives, was established by the Diels–Alder reaction of 1-substituted dienes with cyclopentenone followed by the asymmetric epoxidation of the resulting indene derivatives and then the Ritter reaction. These bulky cis-aminoindanol derivatives are very effective as chiralauxiliaries and nitrogen sources in the asymmetric 6π-azaelectrocyclization
Catalytic, Enantioselective β-Protonation through a Cooperative Activation Strategy
作者:Michael H. Wang、David Barsoum、C. Benjamin Schwamb、Daniel T. Cohen、Brian C. Goess、Matthias Riedrich、Audrey Chan、Brooks E. Maki、Rama K. Mishra、Karl A. Scheidt
DOI:10.1021/acs.joc.7b00334
日期:2017.5.5
only feasible, but also adaptable to a kinetic resolution of secondaryalcohols through NHC-catalyzed acylation. In-depth analysis of this process determined that careful catalyst and solvent pairing is critical for optimal yield and selectivity; proper choice of nonpolar solvent provided improved yield through suppression of an oxidative side reaction, while employment of a cooperative catalytic approach
Highly Stereoselective Asymmetric 6π-Azaelectrocyclization Utilizing the Novel 7-Alkyl Substituted <i>cis</i>-1-Amino-2-indanols: Formal Synthesis of 20-Epiuleine
作者:Katsunori Tanaka、Shigeo Katsumura
DOI:10.1021/ja026464+
日期:2002.8.1
Highly stereoselective asymmetric 6pi-azaelectrocyclization was achieved with generality, based on the reaction between the (E)-3-carbonyl-2,4,6-trienal compounds and the (-)-7-alkyl-cis-1-amino-2-indanol derivatives as the effective novel chiral amines. Furthermore, the chiralauxiliaries of the cyclized products obtained were efficiently removed by the novel manganese dioxide oxidation under remarkably
Development of Highly Stereoselective Asymmetric 6π-Azaelectrocyclization of Conformationally Flexible Linear 1-Azatrienes. From Determination of Multifunctional Chiral Amines, 7-Alkyl <i>cis</i>-1-Amino-2-indanols, to Application as a New Synthetic Strategy: Formal Synthesis of 20-Epiuleine
The highlystereoselective asymmetric 6π-azaelectrocyclization was achieved as a general synthetic method based on the reaction between the (E)-3-carbonyl-2,4,6-trienal compounds and the (−)-7-alkyl-cis-1-amino-2-indanol derivatives which are effective chiral amines. The 7-alkyl-substituted 2-indanol moiety of the cyclized products was efficiently removed by the novel manganese dioxide oxidation under
Asymmetric Synthesis of Chiral 1,3-Diaminopropanols: Bisoxazolidine-Catalyzed CC Bond Formation with α-Keto Amides
作者:Hanhui Xu、Christian Wolf
DOI:10.1002/anie.201105778
日期:2011.12.16
Three high‐yielding steps lead to the formation of chiral 1,3‐diaminopropanols from aliphatic and aromatic α‐keto amides. In this approach, a nitroaldol reaction, which is catalyzed by Cu(SO2CF3)2 and the bisoxazolidine ligand L1, is followed by two mild reduction reactions (see scheme). Laborious protection and deprotection steps can be avoided by using this method.