Catalyst-Free [2,3]-Sigmatropic Rearrangement Reactions of Photochemically Generated Ammonium Ylides

Synthesis ◽  
2019 ◽  
Vol 51 (23) ◽  
pp. 4348-4358 ◽  
Author(s):  
Fang Li ◽  
Feifei He ◽  
Rene M. Koenigs
Keyword(s):  
Visible Light ◽  
Sigmatropic Rearrangement ◽  
Tertiary Amines ◽  
Amino Esters ◽  
Catalyst Free ◽  
Rearrangement Reaction ◽  
Rearrangement Reactions ◽  
Free Ammonium

The rearrangement reaction of ammonium ylides furnishes valuable α,α-disubstituted amino esters. In this work, we describe the visible-light photolysis reaction of aryldiazoacetates in the presence of tertiary amines that react via a free ammonium ylide in a sigmatropic rearrangement reaction to provide amino esters in moderate to very good yields (33 examples, up to 97% yield).

Visible-light-initiated Catalyst-free Oxidative Cleavage of Triaryl-Substituted Alkenes C=C Bonds under Ambient Conditions

2021 ◽  
Author(s):  
Wenjing Li ◽  
Shun Li ◽  
Lihua Luo ◽  
Yichen Ge ◽  
Jiaqi Xu ◽  
...  
Keyword(s):  
Visible Light ◽  
Room Temperature ◽  
Ambient Air ◽  
Oxidative Cleavage ◽  
Ambient Conditions ◽  
Blue Led ◽  
Catalyst Free

The catalyst-free oxidative cleavage of (Z)-triaryl-substituted alkenes bearing pyridyl motif with ambient air under irradiation of blue LED at room temperature has been developed. The reaction was facile and scalable,...

Visible light catalyzed Mannich reaction between tert-amines and silyl diazoenolates

2017 ◽  
Vol 15 (35) ◽  
pp. 7369-7373 ◽  
Author(s):  
Mukund M. D. Pramanik ◽  
Savita B. Nagode ◽  
Ruchir Kant ◽  
Namrata Rastogi
Keyword(s):  
Visible Light ◽  
Mannich Reaction ◽  
Tertiary Amines

The present work documents the α-C–H functionalization of tertiary amines via the visible light catalyzed Mannich reaction with silyl diazoenolates.

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.

Recent Developments on Catalyst‐Free, Visible‐Light‐Triggered Synthesis of Heterocyclic Scaffolds and Their Mechanistic Study

2021 ◽  
Vol 6 (36) ◽  
pp. 9684-9700
Author(s):  
Munmee Goswami ◽  
Arup Dutta ◽  
Pooja Paul ◽  
Rishanlang Nongkhlaw
Keyword(s):  
Visible Light ◽  
Mechanistic Study ◽  
Catalyst Free ◽  
Recent Developments

scholarly journals Visible Light Promoted, Catalyst‐Free Radical Carbohydroxylation and Carboetherification under Mild Biomimetic Conditions

2020 ◽  
Author(s):  
Lisa‐Marie Altmann ◽  
Viviane Zantop ◽  
Pia Wenisch ◽  
Nina Diesendorf ◽  
Markus R. Heinrich
Keyword(s):  
Free Radical ◽  
Visible Light ◽  
Catalyst Free

scholarly journals Theoretical Study of Sigmatropic Rearrangement of Cycloprop-2-en-1-ol and its Fluorine Derivatives: Pericyclic or Pseudopericyclic Character from NICS and LLPE

2019 ◽  
Vol 31 (3) ◽  
pp. 597-601
Author(s):  
A. Sangeetha ◽  
A. Thaminum Ansari ◽  
Jebakumar Jeevanandam ◽  
S. Jayaprakash
Keyword(s):  
Oxygen Atom ◽  
Gas Phase ◽  
Energy Barrier ◽  
Fluorine Atom ◽  
Theoretical Study ◽  
Lone Pair ◽  
Sigmatropic Rearrangement ◽  
Nucleus Independent Chemical Shift ◽  
Lone Pair Electron ◽  
Rearrangement Reaction

Sigmatropic rearrangement reaction of cycloprop-2-en-1-ol and its fluorine derivatives has been studied theoretically in gas phase and its energy barrier has been calculated. Nucleus-independent chemical shift (NICS) shows sigmatropic rearrangement of cycloprop-2-en-1-ol is pericyclic in nature whereas fluorine derivatives show pseudopericyclic and pericyclic nature. Substitution of fluorine atom at ring is found to increase the energy barrier for –OH migration, while substitution at oxygen atom reduces the barrier. To know the involvement of lone pair of electrons during the reaction, lone pair electron present on oxygen atom is locked by hydrogen bonding. CR-CCSD(T)/6-311+G** levels are used to study the reactions more accurately.

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