Photoredox catalysis on unactivated substrates with strongly reducing iridium photosensitizers

Chemical Science, Journal Year: 2021, Volume and Issue: 12(11), P. 4069 - 4078

Published: Jan. 1, 2021

Photoredox catalysis has emerged as a powerful strategy in synthetic organic chemistry, but substrates that are difficult to reduce either require complex reaction conditions or not amenable at all photoredox transformations. In this work, we show strong bis-cyclometalated iridium photoreductants with electron-rich β-diketiminate (NacNac) ancillary ligands enable high-yielding transformations of challenging very simple only single sacrificial reagent. Using blue green visible-light activation demonstrate variety reactions, which include hydrodehalogenation, cyclization, intramolecular radical addition, and prenylation via radical-mediated pathways, optimized the photocatalyst reductant/hydrogen atom donor. Many these reactions involve organobromide organochloride past have had limited utility catalysis. This work paves way for continued expansion substrate scope

Language: Английский

---

Copper‐Photocatalyzed Hydroboration of Alkynes and Alkenes

Angewandte Chemie International Edition, Journal Year: 2021, Volume and Issue: 60(26), P. 14498 - 14503

Published: March 29, 2021

The photocatalytic hydroboration of alkenes and alkynes is reported. use newly-designed copper photocatalysts with B

Language: Английский

---

Chemoselective catalytic hydrodefluorination of trifluoromethylalkenes towards mono-/gem-di-fluoroalkenes under metal-free conditions

Nature Communications, Journal Year: 2021, Volume and Issue: 12(1)

Published: May 14, 2021

Abstract Fluorine-containing moieties show significant effects in improving the properties of functional molecules. Consequently, efficient methods for installing them into target compounds are great demand, especially those enabled by metal-free catalysis. Here we a diazaphospholene-catalyzed hydrodefluorination trifluoromethylalkenes to chemoselectively construct gem -difluoroalkenes and terminal monofluoroalkenes simple adjustment reactant stoichiometry. This features mild reaction conditions, good group compatibility, almost quantitative yields both product types. Stoichiometric experiments indicated stepwise mechanism: hydridic addition fluoroalkenes subsequent β -F elimination from hydrophosphination intermediates. Density theory calculations disclosed origin chemoselectivity, regioselectivity stereoselectivity, suggesting an electron-donating effect alkene-terminal fluorine atom.

Language: Английский

---

C–F bond functionalizations of trifluoromethyl groups via radical intermediates

Chinese Chemical Letters, Journal Year: 2021, Volume and Issue: 33(3), P. 1193 - 1198

Published: Aug. 12, 2021

Language: Английский

---

Visible-light mediated catalytic asymmetric radical deuteration at non-benzylic positions

Nature Communications, Journal Year: 2022, Volume and Issue: 13(1)

Published: Aug. 1, 2022

Abstract Site- and enantioselective incorporation of deuterium into organic compounds is broad interest in synthesis, especially within the pharmaceutical industry. While catalytic approaches relying on two-electron reaction manifolds have allowed for stereoselective delivery a formal deuteride (D – ) or deuteron + at benzylic positions, complementary strategies that make use one-electron atom transfer target non-benzylic positions remain elusive. Here we report photochemical approach asymmetric radical deuteration by utilizing readily available peptide- sugar-derived thiols as catalyst inexpensive oxide source. This metal-free platform enables four types deuterofunctionalization reactions exocyclic olefins allows with high levels enantioselectivity incorporation. Computational studies reveal attractive non-covalent interactions are responsible stereocontrol. We anticipate our findings will open up new avenues deuteration.

Language: Английский

---