Enantioselective Alkynylation of Unstabilized Cyclic Iminium Ions

ACS Catalysis ◽  
2020 ◽  
Vol 10 (23) ◽  
pp. 13820-13824
Author(s):  
Weiye Guan ◽  
Samantha O. Santana ◽  
Jennie Liao ◽  
Kelci Henninger ◽  
Mary P. Watson
Keyword(s):  
Iminium Ions

Enantioselective Radical Functionalization of Imines and Iminium Intermediates via Visible Light Photoredox Catalysis

Synthesis ◽  
2020 ◽  
Author(s):  
Jia-Jia Zhao ◽  
Hong-Hao Zhang ◽  
Shouyun Yu
Keyword(s):  
Visible Light ◽  
Asymmetric Synthesis ◽  
Carbonyl Compounds ◽  
Asymmetric Reduction ◽  
Chemical Transformations ◽  
Photoredox Catalysis ◽  
Radical Coupling ◽  
Mild Conditions ◽  
Iminium Ions ◽  
Radical Functionalization

Visible light photoredox catalysis has recently emerged as a powerful tool for the development of new and valuable chemical transformations under mild conditions. Visible-light promoted enantioselective radical transformations of imines and iminium intermediates provide new opportunities for the asymmetric synthesis of amines and asymmetric β-functionalization of unsaturated carbonyl compounds. In this review, the advance in the catalytic asymmetric radical functionalization of imines, as well as iminium intermediates, are summarized. 1 Introduction 2 The enantioselective radical functionalization of imines 2.1 Asymmetric reduction 2.2 Asymmetric cyclization 2.3 Asymmetric addition 2.4 Asymmetric radical coupling 3 The enantioselective radical functionalization of iminium ions 3.1 Asymmetric radical alkylation 3.2 Asymmetric radical acylation 4 Conclusion

Facile synthesis of indene and fluorene derivatives through AlCl3 -catalyzed cyclization of in situ formed iminium ions

2017 ◽  
Vol 31 (12) ◽  
pp. e3863 ◽  
Author(s):  
Lei Chen ◽  
Wei Teng ◽  
Xin-Le Geng ◽  
Yi-Fan Zhu ◽  
Yong-Hong Guan ◽  
...  
Keyword(s):  
Facile Synthesis ◽  
Iminium Ions

ChemInform Abstract: Asymmetric Addition of Chiral Boronate Complexes to Cyclic Iminium Ions.

ChemInform ◽  
2014 ◽  
Vol 45 (29) ◽  
pp. no-no
Author(s):  
Maziar Mohiti ◽  
Constantinos Rampalakos ◽  
Kathryn Feeney ◽  
Daniele Leonori ◽  
Varinder K. Aggarwal
Keyword(s):  
Asymmetric Addition ◽  
Iminium Ions

Visible-Light-Promoted CC Bond Cleavage: Photocatalytic Generation of Iminium Ions and Amino Radicals

2012 ◽  
Vol 51 (32) ◽  
pp. 8050-8053 ◽  
Author(s):  
Shunyou Cai ◽  
Xinyang Zhao ◽  
Xinbo Wang ◽  
Qisong Liu ◽  
Zigang Li ◽  
...  
Keyword(s):  
Visible Light ◽  
Bond Cleavage ◽  
Iminium Ions

Oxidation cyclischer α-Aminoketone / Oxidation of Cyclic α-Aminoketones

2007 ◽  
Vol 62 (2) ◽  
pp. 249-260 ◽  
Author(s):  
Hans Möhrle ◽  
Christiane Rohn
Keyword(s):  
Carbonyl Group ◽  
Acid Catalysis ◽  
Base Catalysis ◽  
Amino Ketone ◽  
Ring Contraction ◽  
Hydroxycarboxylic Acid ◽  
Primary Products ◽  
Tautomeric Forms ◽  
Iminium Ions ◽  
Identical Product

The 1,2,3,4-tetrahydro-isoquinolin-4-one 4 reacts as an α-amino ketone with periodate to give various products, the major compound being 1-hydroxy-1,2-dihydro-3,4-isoquinolinedione 12. Upon stepwise oxidation with Hg(II)-EDTA the 4-hydroxyisoquinolinium ion 14 is detected as an intermediate and its further oxidation with periodate gives rise to an almost identical product spectrum. Because 12 represents a carbinolamide with an additional 4-carbonyl group, this type was examined first. Acid catalysis was used because the reactive species mostly are iminium ions. With cyclic 1,3- dicarbonyl compounds, 1-substituted derivatives 17a, b are formed.With linear species 1-substitution is also observed, but the tautomeric forms 19a - c are obtained. The stable enones 24a, b result from alkyl ketones by ready autoxidation of the primary products. Base catalysis induces a ring contraction of 12 to the hydroxycarboxylic acid 25. Reaction of 12 with aniline and phenylhydrazine yields the easily oxidizable 1-substitution products 28 and 31.

scholarly journals One-pot functionalisation of N-substituted tetrahydroisoquinolines by photooxidation and tunable organometallic trapping of iminium intermediates

2014 ◽  
Vol 10 ◽  
pp. 2981-2988 ◽  
Author(s):  
Joshua P Barham ◽  
Matthew P John ◽  
John A Murphy
Keyword(s):  
Visible Light ◽  
Tertiary Amines ◽  
One Pot ◽  
Carbon Nucleophiles ◽  
Iminium Salts ◽  
Iminium Ions ◽  
Nucleophilic Trapping ◽  
Limited Scope

Nucleophilic trapping of iminium salts generated via oxidative functionalisation of tertiary amines is well established with stabilised carbon nucleophiles. The few reports of organometallic additions have limited scope of substrate and organometallic nucleophile. We report a novel, one-pot methodology that functionalises N-substituted tetrahydroisoquinolines by visible light-assisted photooxidation, followed by trapping of the resultant iminium ions with organometallic nucleophiles. This affords 1,2-disubstituted tetrahydroisoquinolines in moderate to excellent yields.

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