Asymmetric synthesis of heterocyclic chloroamines and aziridines by enantioselective protonation of catalytically generated enamines

We report a method for the synthesis of chiral vicinal chlo-roamines via asymmetric protonation of catalytically gener-ated prochiral chloroenamines using chiral Brønsted acids. The process is highly enantioselective, with the origin of asymmetry and catalyst substituent effects elucidated by DFT calculations. We show the utility of the method as an approach to the synthesis of a broad range of heterocycle-substituted aziridines by treatment of the chloroamines with base in a one-pot process, as well as the utility of the process to allow access to vicinal diamines.

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Enantioselective Photocycloaddition Mediated by Chiral Brønsted Acids: Asymmetric Synthesis of the Rocaglamides

Journal of the American Chemical Society ◽

10.1021/ja062621j ◽

2006 ◽

Vol 128 (24) ◽

pp. 7754-7755 ◽

Cited By ~ 112

Author(s):

Baudouin Gerard ◽

Sheharbano Sangji ◽

Daniel J. O'Leary ◽

John A. Porco

Keyword(s):

Asymmetric Synthesis ◽

Bronsted Acids ◽

Chiral Brønsted Acids

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A Scalable, One-Pot Synthesis of 1,2,3,4,5-Pentacarbomethoxycyclopentadiene

Synthesis ◽

10.1055/s-0037-1611650 ◽

2019 ◽

Vol 51 (05) ◽

pp. 1135-1138 ◽

Cited By ~ 1

Author(s):

M. Radtke ◽

Caroline Dudley ◽

Jacob O’Leary ◽

Tristan Lambert

Keyword(s):

Ambient Temperature ◽

Organic Acid ◽

Lewis Acids ◽

Bronsted Acids ◽

Synthetic Route ◽

One Pot ◽

One Pot Synthesis ◽

High Reaction ◽

Chiral Brønsted Acids ◽

Silicon Based

1,2,3,4,5-Pentacarbomethoxycyclopentadiene (PCCP) is a strong organic acid and a precursor to useful organocatalysts, including chiral Brønsted acids and silicon-based Lewis acids. The synthetic route to PCCP, first reported in 1942, is inconvenient for a number of reasons. The two-step synthesis requires the purification of intermediates from intractable side-products, high reaction temperatures, and extensive labor (3 days). We have developed an improved procedure that delivers PCCP efficiently in 24 hours in one pot at ambient temperature and without isolation.

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Asymmetric synthesis of isoquinolinonaphthyridines catalyzed by a chiral Brønsted acid

Organic & Biomolecular Chemistry ◽

10.1039/c7ob01527e ◽

2017 ◽

Vol 15 (31) ◽

pp. 6474-6477 ◽

Cited By ~ 8

Author(s):

Jianjun Li ◽

Yiwei Fu ◽

Cong Qin ◽

Yang Yu ◽

Hao Li ◽

...

Keyword(s):

Asymmetric Synthesis ◽

Cyclization Reaction ◽

Bronsted Acids ◽

Bronsted Acid ◽

Brønsted Acid ◽

Brönsted Acid ◽

Chiral Bronsted Acid ◽

Chiral Brønsted Acids

A mild and efficient asymmetric cyclization reaction catalyzed by chiral Brønsted acids has been developed for the synthesis of chiral isoquinolinonaphthyridines.

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One-Pot Synthesis and Conformational Analysis of 6-Membered Cyclic Iodonium Salts

10.26434/chemrxiv.12234665 ◽

2020 ◽

Author(s):

Lucien Caspers ◽

Julian Spils ◽

Mattis Damrath ◽

Enno Lork ◽

Boris Nachtsheim

Keyword(s):

Conformational Analysis ◽

Bronsted Acids ◽

One Pot ◽

Benzyl Alcohols ◽

Iodonium Salts ◽

Efficient Approach ◽

One Pot Synthesis ◽

Diaryliodonium Salts

In this article we describe an efficient approach for the synthesis of cyclic diaryliodonium salts. The method is based on benzyl alcohols as starting materials and consists of an Friedel-Crafts-arylation/oxidation sequence. Besides a deep optimization, particluar focusing on the choice and ratios of the utilized Bronsted-acids and oxidants, we explore the substrate scope of this transformation. We also discuss an interesting isomerism of cyclic iodonium salts substituted with aliphatic substituents at the bridge head carbon. <br>

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Indium Bromide-catalyzed Unprecedented Hydrogenolysis: A Novel One-Pot Synthesis of Per-O-Acetylated β-carboxymethyl O and S-glycosides

Current Organic Chemistry ◽

10.2174/1385272824999200407093625 ◽

2020 ◽

Vol 24 (8) ◽

pp. 900-908

Author(s):

Ram Naresh Yadav ◽

Amrendra K Singh ◽

Bimal Banik

Keyword(s):

Asymmetric Synthesis ◽

Chiral Auxiliary ◽

Bioactive Molecules ◽

One Pot ◽

Enantiomerically Pure ◽

Stereoselective Glycosylation ◽

One Pot Synthesis ◽

Wide Range

Numerous O (oxa)- and S (thia)-glycosyl esters and their analogous glycosyl acids have been accomplished through stereoselective glycosylation of various peracetylated bromo sugar with benzyl glycolate using InBr3 as a glycosyl promotor followed by in situ hydrogenolysis of resulting glycosyl ester. A tandem glycosylating and hydrogenolytic activity of InBr3 has been successfully investigated in a one-pot procedure. The resulting synthetically valuable and virtually unexplored class of β-CMGL (glycosyl acids) could serve as an excellent potential chiral auxiliary in the asymmetric synthesis of a wide range of enantiomerically pure medicinally prevalent β-lactams and other bioactive molecules of diverse medicinal interest.

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