scholarly journals Metal-free oxidative cross-coupling enabled practical synthesis of atropisomeric QUINOL and its derivatives

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Peng-Ying Jiang ◽  
Kai-Fang Fan ◽  
Shaoyu Li ◽  
Shao-Hua Xiang ◽  
Bin Tan
Keyword(s):  
Asymmetric Catalysis ◽  
Kinetic Resolution ◽  
Academic Research ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Industrial Applications ◽  
Lewis Base ◽  
Production Costs ◽  
Metal Free ◽  
Base Catalysts

AbstractAs an important platform molecule, atropisomeric QUINOL plays a crucial role in the development of chiral ligands and catalysts in asymmetric catalysis. However, efficient approaches towards QUINOL remain scarce, and the resulting high production costs greatly impede the related academic research as well as downstream industrial applications. Here we report a direct oxidative cross-coupling reaction between isoquinolines and 2-naphthols, providing a straightforward and scalable route to acquire the privileged QUINOL scaffolds in a metal-free manner. Moreover, a NHC-catalyzed kinetic resolution of QUINOL N-oxides with high selectivity factor is established to access two types of promising axially chiral Lewis base catalysts in optically pure forms. The utility of this methodology is further illustrated by facile transformations of the products into QUINAP, an iconic ligand in asymmetric catalysis.

scholarly journals Developing a Methodology for Catalytic Asymmetric Crotylation of Aldehydes

Synlett ◽  
2021 ◽  
Author(s):  
Andrei V. Malkov ◽  
Aleksandr E. Rubtsov
Keyword(s):  
Kinetic Resolution ◽  
Lewis Base ◽  
Chiral Auxiliaries ◽  
Organometallic Reagents ◽  
Total Syntheses ◽  
Base Catalysts ◽  
Homoallylic Alcohols ◽  
Stereogenic Centers ◽  
Long Time ◽  
Lewis Base Catalysts

AbstractAsymmetric crotylation has firmly earned a place among the set of valuable synthetic tools for stereoselective construction of carbon skeletons. For a long time the field was heavily dominated by reagents bearing stoichiometric chiral auxiliaries, but now catalytic methods are gradually taking center stage, and the area continues to develop rapidly. This account focuses primarily on preformed organometallic reagents based on silicon and, to some extent, boron. It narrates our endeavors to design new and efficient chiral Lewis base catalysts for the asymmetric addition of crotyl(trichloro)silanes to aldehydes. It also covers the development of a novel protocol for kinetic resolution of racemic secondary allylboronates to give enantio- and diastereomerically enriched linear homoallylic alcohols. As a separate topic, cross-crotylation of aldehydes by using enantiopure branched homoallylic alcohols as a source of crotyl groups is discussed. Finally, the synthetic credentials of the developed methodology are illustrated by total syntheses of marine natural products, in which crotylation plays a key role in setting up stereogenic centers.1 Introduction2 Pyridine N-Oxides as Lewis Base Catalysts3 Bipyridine N,N′-Dioxides as Lewis Base Catalysts4 Chiral Allylating Reagents5 Synthetic Applications6 Concluding Remarks

Selectfluor-induced C(sp2)–O coupling reaction of N-substituted anilines with hydroxylamine derivatives

2018 ◽  
Vol 16 (33) ◽  
pp. 6017-6024 ◽  
Author(s):  
Bin Sun ◽  
Shi Yin ◽  
Xiaohui Zhuang ◽  
Can Jin ◽  
Weike Su
Keyword(s):  
Coupling Reaction ◽  
Cross Coupling ◽  
Coupling Reactions ◽  
Substituted Anilines ◽  
Metal Free ◽  
Cross Coupling Reactions ◽  
Hydroxylamine Derivatives

We developed a novel metal-free method for the construction of C(sp2)–O bonds via oxidative cross-coupling reactions between various N-substituted anilines and hydroxylamine derivatives just using commercially available Selectfluor as an oxidant.

scholarly journals Biocatalytic Dynamic Kinetic Resolution for the Synthesis of Atropisomeric Biaryl N-Oxide Lewis Base Catalysts

2016 ◽  
Vol 128 (36) ◽  
pp. 10913-10917 ◽  
Author(s):  
Samantha Staniland ◽  
Ralph W. Adams ◽  
Joseph J. W. McDouall ◽  
Irene Maffucci ◽  
Alessandro Contini ◽  
...  
Keyword(s):  
Kinetic Resolution ◽  
Lewis Base ◽  
Dynamic Kinetic Resolution ◽  
Base Catalysts ◽  
Lewis Base Catalysts

ChemInform Abstract: Selective Synthesis of Partially Protected Nonsymmetric Biphenols by Reagent- and Metal-Free Anodic Cross-Coupling Reaction.

ChemInform ◽  
2016 ◽  
Vol 47 (52) ◽  
Author(s):  
Anton Wiebe ◽  
Dieter Schollmeyer ◽  
Katrin M. Dyballa ◽  
Robert Franke ◽  
Siegfried R. Waldvogel
Keyword(s):  
Coupling Reaction ◽  
Cross Coupling ◽  
Selective Synthesis ◽  
Metal Free ◽  
Cross Coupling Reaction

Transition metal-free tandem pyridinyl–allyl–allyl cross-coupling reaction

2017 ◽  
Vol 47 (18) ◽  
pp. 1668-1675 ◽  
Author(s):  
Lili Zhang ◽  
Zhengkai Chen ◽  
Hongli Li ◽  
Wenguang Yin ◽  
Jianfeng Xu ◽  
...  
Keyword(s):  
Transition Metal ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Metal Free ◽  
Cross Coupling Reaction

An Iodide-Mediated Transition-Metal-Free Strategy towards Unsymmetrical Diaryl Sulfides via Arylhydrazines and Thiols

Synthesis ◽  
2019 ◽  
Vol 52 (05) ◽  
pp. 727-734 ◽  
Author(s):  
Farnaz Jafarpour ◽  
Mohammad Asadpour ◽  
Meysam Azizzade ◽  
Mehran Ghasemi ◽  
Saideh Rajai-Daryasarei
Keyword(s):  
Transition Metal ◽  
Room Temperature ◽  
Bond Formation ◽  
Antidepressant Drug ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Potential Utility ◽  
Metal Free ◽  
Cross Coupling Reaction ◽  
High Yields

A mild, scalable iodine-mediated oxidative cross-coupling reaction of arylhydrazines and thiols for construction of thioethers (sulfides) in the absence of any transition metals or photocatalysts is disclosed. A variety of unsymmetrical diaryl sulfides with broad substrate scope both on thiols and hydrazines were synthesized in high yields in water at room temperature. Furthermore, to demonstrate the utility of the protocol, the above C–S bond formation was applied in the synthesis of the key structure of vortioxetine as an antidepressant drug. The gram-scale outcome also added to the potential utility of this protocol.

ChemInform Abstract: Metal-Free Cross-Coupling Reaction of Aldehydes with Disulfides by Using DTBP as an Oxidant under Solvent-Free Conditions.

ChemInform ◽  
2014 ◽  
Vol 45 (37) ◽  
pp. no-no
Author(s):  
Jing-Wen Zeng ◽  
Yi-Chen Liu ◽  
Ping-An Hsieh ◽  
Yu-Ting Huang ◽  
Chih-Lun Yi ◽  
...  
Keyword(s):  
Coupling Reaction ◽  
Cross Coupling ◽  
Solvent Free ◽  
Metal Free ◽  
Cross Coupling Reaction ◽  
Solvent Free Conditions
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