Organic Photocatalytic Cyclization of Polyenes: A Visible‐Light‐Mediated Radical Cascade Approach

Yang, Zhongbo; Li, Han; Zhang, Long; Zhang, Ming‐Tian; Cheng, Jin‐Pei; Luo, Sanzhong

doi:10.1002/chem.201503118

Cited by 30 publications

(25 citation statements)

References 67 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…148 In this regard, catalytic protocols which utilize Lewis acids to enhance the rate of radical trapping have been reported. 149 Of particular note is a report by Yoon and co-workers demonstrating that conjugate additions of α-amino radicals can be rendered asymmetric through the use of a chiral i -BuPyBox-ligated Lewis acid catalyst (Scheme 31a). 33 Here, photoredox catalysis mediates generation of the α-amino radical and the Lewis acid complex controls stereoselectivity in the subsequent addition step.…”

Section: Photoredox Lewis Acid Catalysismentioning

confidence: 99%

Photoredox Catalysis in Organic Chemistry

2016

View full text Add to dashboard Cite

In recent years, photoredox catalysis has come to the forefront in organic chemistry as a powerful strategy for the activation of small molecules. In a general sense, these approaches rely on the ability of metal complexes and organic dyes to convert visible light into chemical energy by engaging in single-electron transfer with organic substrates, thereby generating reactive intermediates. In this Perspective, we highlight the unique ability of photoredox catalysis to expedite the development of completely new reaction mechanisms, with particular emphasis placed on multicatalytic strategies that enable the construction of challenging carbon–carbon and carbon–heteroatom bonds.

show abstract

Section: Photoredox Lewis Acid Catalysismentioning

confidence: 99%

Photoredox Catalysis in Organic Chemistry

2016

View full text Add to dashboard Cite

show abstract

“…However, the addition of LiBr helped to favor the enol tautomer, allowing facile cyclization to 135 (Scheme 35). 174 …”

Section: Photoinduced Electron Transfermentioning

confidence: 99%

Dual Catalysis Strategies in Photochemical Synthesis

2016

View full text Add to dashboard Cite

The interaction between an electronically excited photocatalyst and an organic molecule can result in the genertion of a diverse array of reactive intermediates that can be manipulated in a variety of ways to result in synthetically useful bond constructions. This Review summarizes dual-catalyst strategies that have been applied to synthetic photochemistry. Mechanistically distinct modes of photocatalysis are discussed, including photoinduced electron transfer, hydrogen atom transfer, and energy transfer. We focus upon the cooperative interactions of photocatalysts with redox mediators, Lewis and Brønsted acids, organocatalysts, enzymes, and transition metal complexes.

show abstract

“…It can stabilize the radical cation intermediates due to its high hydrogen bonding donor strength, polarity, and ionizing power, may participate in the radical cyclization in step 3 to accelerate it and has the property of dissolving large quantities of oxygen which has been used as a redox catalyst in this reaction. [10,21] However, the exact reason for the effectiveness of HFIP as an additive could not be realized. It is noteworthy that Luo and co-workers utilized HFIP as an efficient solvent for eosin Y-based photocatalytic stereoselective radical cascade cyclization of polyenes.…”

Section: Full Paper Ascwiley-vchdementioning

confidence: 99%

Solvent Dependent Divergent Reactivity of Electron‐Rich Dienones with and without Visible Light: Access to Cyclopropanated Furans and Butenolides

Saha

Das

2019

Adv Synth Catal

View full text Add to dashboard Cite

Visible light excitation of electron-rich dienones in isopropanol solvent under ambient conditions using hexafluoroisopropanol (HFIP) as an additive promotes intramolecular radical cascade cyclization to afford cyclopropanated furans. Molecular dioxygen in the air serves as a redox catalyst in this reaction which is proposed to proceed through a radical cation intermediate generated by single-electron transfer (SET) from a phototransient dienone to oxygen. By changing the solvent from isopropanol to HFIP, exclusive formation of substituted butenolides occurs via ionic cascade cyclization involving E!Z isomerization/lactonization/thiolate addition. HFIP is assumed to act as a medium, hydrogen bond donor catalyst, and a Lewis acid substitute as well. This reaction may be conducted even in the absence of light and no catalyst or reagent is required.

show abstract

Organic Photocatalytic Cyclization of Polyenes: A Visible‐Light‐Mediated Radical Cascade Approach

Cited by 30 publications

References 67 publications

Photoredox Catalysis in Organic Chemistry

Photoredox Catalysis in Organic Chemistry

Dual Catalysis Strategies in Photochemical Synthesis

Solvent Dependent Divergent Reactivity of Electron‐Rich Dienones with and without Visible Light: Access to Cyclopropanated Furans and Butenolides

Contact Info

Product

Resources

About