Visible-Light-Promoted Redox-Neutral Cyclopropanation Reactions of α-Substituted Vinylphosphonates and Other Michael Acceptors with Chloromethyl Silicate as Methylene Transfer Reagent

2018 ◽  
Vol 360 (23) ◽  
pp. 4459-4463 ◽  
Author(s):  
Ting Guo ◽  
Li Zhang ◽  
Xiaobo Liu ◽  
Yewen Fang ◽  
Xiaoping Jin ◽  
...  
Keyword(s):  
Visible Light ◽  
Michael Acceptors

Anionic Cyclometallated platinum(II) Tetrazolato Complexes as Viable Photoredox Catalysts

2018 ◽  
Author(s):  
Anna Maria Ranieri ◽  
Liam Burt ◽  
Stefano Stagni ◽  
Stefano Zacchini ◽  
Brian Skelton ◽  
...  
Keyword(s):  
Solid State ◽  
Visible Light ◽  
Room Temperature ◽  
Functional Group ◽  
Photophysical Properties ◽  
General Structure ◽  
No Emission ◽  
Michael Acceptors ◽  
Catalyzed Reactions

The synthesis, characterization, photophysical and photocatalytic studies of anionic platinum(II) tetrazolato complexes, with the general structure [TBA][Pt(CNC)TzR], are reported, where CNC<sup>2-</sup>represents a doubly cyclometalated 2,4,6-triphenylpyridine, TzR<sup>- </sup>is an anionic 5-substituted tetrazolato ligand (with a variable R functional group) and TBA<sup>+ </sup>is the tetrabutylammonium countercation. The complexes were prepared by substitution of the DMSO ligand in [Pt(CNC)(DMSO)] with the corresponding tetrazolato ligand. No emission from the platinum(II) complexes was detected at room temperature in solution, but the photophysical properties could be assessed in the solid state, where all the complexes display emission bands attributed to aggregates. The platinum(II) complexes were found to facilitate a range of fundamental classes of visible-light-mediated photoredox-catalyzed reactions, including α‑amino C–H functionalization processes, such as Povarov-type reactions and the addition of α-amino C–H bonds across Michael acceptors, in addition to ATRA chemistry, and a hydrodeiodination. With the exception of the hydrodeiodination process, the best Pt(II) catalysts provided turnover numbers of 150–175 in each of these transformations.

Visible Light Photoredox Catalysis: Generation and Addition of N-Aryltetrahydroisoquinoline-Derived α-Amino Radicals to Michael Acceptors

2012 ◽  
Vol 14 (3) ◽  
pp. 672-675 ◽  
Author(s):  
Paul Kohls ◽  
Deepak Jadhav ◽  
Ganesh Pandey ◽  
Oliver Reiser
Keyword(s):  
Visible Light ◽  
Photoredox Catalysis ◽  
Michael Acceptors

scholarly journals Silyl-mediated photoredox-catalyzed Giese reaction: addition of non-activated alkyl bromides

2018 ◽  
Vol 9 (32) ◽  
pp. 6639-6646 ◽  
Author(s):  
Abdellatif ElMarrouni ◽  
Casey B. Ritts ◽  
Jaume Balsells
Keyword(s):  
Visible Light ◽  
Hdac Inhibitor ◽  
Addition Reaction ◽  
Conjugate Addition ◽  
Photoredox Catalysis ◽  
Unsaturated Esters ◽  
Alkyl Bromides ◽  
Michael Acceptors

The development of a conjugate addition reaction of non-activated alkyl bromides to Michael acceptors under visible-light photoredox catalysis is disclosed. A diverse set of alkyl bromides was successfully added to α,β-unsaturated esters and amides. This transformation allowed access to a key intermediate of Vorinostat®, an HDAC inhibitor used to fight cancer and HIV.

A visible-light-activated rhodium complex in enantioselective conjugate addition of α-amino radicals with Michael acceptors

2017 ◽  
Vol 53 (54) ◽  
pp. 7665-7668 ◽  
Author(s):  
Shao-Xia Lin ◽  
Gui-Jun Sun ◽  
Qiang Kang
Keyword(s):  
Visible Light ◽  
Conjugate Addition ◽  
Rhodium Complex ◽  
Michael Acceptors

An efficient enantioselective conjugate addition of photogenerated α-amino radicals to Michael acceptors catalyzed by a single and newly prepared chiral-at-metal rhodium complex was established.

Anionic Cyclometallated platinum(II) Tetrazolato Complexes as Viable Photoredox Catalysts

2018 ◽  
Author(s):  
Anna Maria Ranieri ◽  
Liam Burt ◽  
Stefano Stagni ◽  
Stefano Zacchini ◽  
Brian Skelton ◽  
...  
Keyword(s):  
Solid State ◽  
Visible Light ◽  
Room Temperature ◽  
Functional Group ◽  
Photophysical Properties ◽  
General Structure ◽  
No Emission ◽  
Michael Acceptors ◽  
Catalyzed Reactions

The synthesis, characterization, photophysical and photocatalytic studies of anionic platinum(II) tetrazolato complexes, with the general structure [TBA][Pt(CNC)TzR], are reported, where CNC<sup>2-</sup>represents a doubly cyclometalated 2,4,6-triphenylpyridine, TzR<sup>- </sup>is an anionic 5-substituted tetrazolato ligand (with a variable R functional group) and TBA<sup>+ </sup>is the tetrabutylammonium countercation. The complexes were prepared by substitution of the DMSO ligand in [Pt(CNC)(DMSO)] with the corresponding tetrazolato ligand. No emission from the platinum(II) complexes was detected at room temperature in solution, but the photophysical properties could be assessed in the solid state, where all the complexes display emission bands attributed to aggregates. The platinum(II) complexes were found to facilitate a range of fundamental classes of visible-light-mediated photoredox-catalyzed reactions, including α‑amino C–H functionalization processes, such as Povarov-type reactions and the addition of α-amino C–H bonds across Michael acceptors, in addition to ATRA chemistry, and a hydrodeiodination. With the exception of the hydrodeiodination process, the best Pt(II) catalysts provided turnover numbers of 150–175 in each of these transformations.

Decarboxylative C–C and C–N Bond Formation via Ligand-Accelerated Iron Photocatalysis

2019 ◽  
Author(s):  
Guangshou Feng ◽  
Xiaofei Wang ◽  
Jian Jin
Keyword(s):  
Visible Light ◽  
Carboxylic Acids ◽  
Visible Light Irradiation ◽  
Bond Formation ◽  
Light Irradiation ◽  
Alkyl Radicals ◽  
Michael Acceptors

Through iron photocatalysis, a mild and effective protocol for the decarboxylative C–C and C–N bond formation has been achieved. The carboxylic acids readily underwent radical decarboxylation in the presence of Fe<sub>2</sub>(SO<sub>4</sub>)<sub>3 </sub>and di-(2-picolyl)amine with visible light irradiation. The resultant alkyl radicals then reacted with Michael acceptors or azodicarboxylates to furnish the adducts.<br>

Decarboxylative C–C and C–N Bond Formation via Ligand-Accelerated Iron Photocatalysis

2019 ◽  
Author(s):  
Guangshou Feng ◽  
Xiaofei Wang ◽  
Jian Jin
Keyword(s):  
Visible Light ◽  
Carboxylic Acids ◽  
Visible Light Irradiation ◽  
Bond Formation ◽  
Light Irradiation ◽  
Alkyl Radicals ◽  
Michael Acceptors

Through iron photocatalysis, a mild and effective protocol for the decarboxylative C–C and C–N bond formation has been achieved. The carboxylic acids readily underwent radical decarboxylation in the presence of Fe<sub>2</sub>(SO<sub>4</sub>)<sub>3 </sub>and di-(2-picolyl)amine with visible light irradiation. The resultant alkyl radicals then reacted with Michael acceptors or azodicarboxylates to furnish the adducts.<br>

Aerobic C–H Functionalization Using Pyrenedione as the Photocatalyst

Synthesis ◽  
2020 ◽  
Vol 52 (17) ◽  
pp. 2512-2520
Author(s):  
Jie Wu ◽  
Dejiang Huang ◽  
Yuannian Zhang ◽  
Xin Yang
Keyword(s):  
Visible Light ◽  
Ambient Conditions ◽  
Blue Led ◽  
Led Light ◽  
Unique Character ◽  
Turnover Process ◽  
Michael Acceptors

We disclose a visible-light-promoted aerobic alkylation of activated C(sp3)–H bonds using pyrenedione (PYD) as the photocatalyst. Direct C–H bond alkylation of tetrahydrofuran with alkylidenemalononitriles is accomplished in over 90% yield in the presence of 5 mol% of PYD and 18 W blue LED light under ambient conditions. The substrate scope is extended to ethers, thioethers, and allylic C–H bonds in reactions with various electrophilic Michael acceptors. The catalytic turnover process is facilitated by oxygen. Our work represents the first example of using PYD as a photocatalyst to promote C(sp3)–H alkylation, revealing the unique character of PYD as a novel organophotocatalyst.

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