edgepedia

Physical world and mathematics

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Photonics West

Photonics West is SPIE's annual six-day winter conference and exhibition for optics and photonics, held at the Moscone Center in San Francisco since 2010, drawing over 24,000 attendees.

Photophoretic levitation

Photophoretic levitation is the lifting of an object by light, which heats it relative to the surrounding gas so gas molecules push it upward; demonstrated levitation includes centimeter-scale plates for exploring Earth's mesosphere.

Photophoretic trapping

Photophoretic trapping is the stable three-dimensional confinement of a light-absorbing particle in air, using forces from uneven heating of the particle by light, where optical tweezers struggle.

Photoredox activation of alkylsilicates

Photoredox activation of alkylsilicates is a synthetic method that uses visible-light photoredox catalysts to oxidize alkylbis(catecholato)silicate salts, cleaving the silicon–carbon bond to release alkyl radicals that form C(sp3)–C(sp2) bonds with nickel catalysts under mild, base-free conditions.

Photoredox alkene dicarbofunctionalization

Photoredox alkene dicarbofunctionalization is a family of visible-light reactions adding two distinct carbon groups across an alkene in one photochemical operation, typically via radical-polar crossover.

Photoredox Birch-type reduction

A photoredox Birch-type reduction is a light-driven variant of the Birch reduction in which a visible-light photocatalyst, rather than alkali metal in ammonia, converts arenes to 1,4-cyclohexadienes.

Photoredox catalysis

Photoredox catalysis is a synthetic method in which a photocatalyst absorbs visible light and transfers a single electron to organic substrates, forming bonds under mild conditions.

Photoredox decarboxylative borylation of redox-active esters

Photoredox decarboxylative borylation of redox-active esters is a radical reaction that converts alkyl carboxylic acids into versatile alkyl boronates, reported in 2017 by the Baran, Aggarwal, and Li groups.

Photoredox decarboxylative C–C bond formation

Photoredox decarboxylative C–C bond formation is a set of visible-light reactions in which carboxylic acids lose carbon dioxide to form radicals that build new carbon–carbon bonds under mild conditions.

Photoredox decarboxylative trifluoromethylation

Photoredox decarboxylative trifluoromethylation is a visible-light reaction in which trifluoroacetic acid releases carbon dioxide to form trifluoromethyl radicals that bond to arenes, used in drug discovery.

Photoredox deracemization of amines

Photoredox deracemization of amines is a set of light-driven catalytic methods that convert racemic amines entirely into a single enantiomer using visible-light photocatalysts, developing rapidly since 2018.

Photoredox direct C–H arylation of heteroarenes

Photoredox direct C–H arylation of heteroarenes joins aryl groups to heteroarene C–H bonds using aryl radicals from visible-light photoredox catalysts, as first shown metal-free with eosin Y in 2012.

Photoredox flow chemistry

Photoredox flow chemistry conducts photocatalytic reactions, in which a photocatalyst transfers single electrons to generate radical intermediates, in continuous-flow reactors that give uniform light exposure and scale from milligrams to kilograms per day.

Photoredox Minisci reaction

The photoredox Minisci reaction is a visible-light version of the Minisci reaction in which a photocatalyst generates carbon radicals that add to the C–H bonds of heteroarenes.

Photoredox NHC catalysis

Photoredox NHC catalysis is a dual-catalysis strategy in organic synthesis that combines N-heterocyclic carbene organocatalysis with photoredox catalysis, using visible light to drive radical reactions under mild conditions.

Photoredox nickel-catalyzed C–O and C–N cross-coupling

Photoredox nickel-catalyzed C–O and C–N cross-coupling is a metallaphotoredox reaction family combining a nickel catalyst with a light-absorbing photoredox catalyst to form carbon–oxygen and carbon–nitrogen bonds.

Photoredox organocatalysis

Photoredox organocatalysis is a dual-catalysis strategy in organic synthesis that merges a visible-light photoredox catalyst with a chiral organocatalyst, pioneered by Nicewicz and MacMillan's 2008 enantioselective α-alkylation of aldehydes.

Photoredox proton-coupled electron transfer

Photoredox proton-coupled electron transfer is a bond-activation strategy in visible-light catalysis where a photoexcited catalyst and an acid or base remove or deliver an electron and a proton together.

Photoredox trifluoromethylation

Photoredox trifluoromethylation is a visible-light method that attaches trifluoromethyl (CF3) groups to organic molecules through radicals, pioneered by Nagib and MacMillan in Nature in 2011.

Photoredox α-amino C–H functionalization

Photoredox α-amino C–H functionalization is a set of visible-light-driven reactions that turn the C–H bond adjacent to nitrogen in amines into carbon–carbon or carbon–heteroatom bonds.

Photoredox-catalyzed alkene carbofunctionalization

Photoredox-catalyzed alkene carbofunctionalization is a family of organic reactions in which visible-light single-electron-transfer catalysis installs carbon-based groups across an alkene's double bond, widely used in drug and natural product synthesis.

Photoredox-catalyzed alkene difunctionalization

Photoredox-catalyzed alkene difunctionalization is a set of synthetic methods that add two functional groups across an alkene in one operation, using visible-light photocatalysts to generate radical intermediates under mild conditions.

Photoredox-catalyzed arene C–H alkylation via radical cations

Photoredox-catalyzed arene C–H alkylation via radical cations is a metal-free method for attaching alkyl groups to arene C–H bonds, reported by the Nicewicz group at UNC in 2020.

Photoredox-catalyzed carboxylation with CO2

Photoredox-catalyzed carboxylation with CO2 is a family of organic reactions in which a visible-light photocatalyst activates carbon dioxide to form carbon–carbon bonds under mild conditions.

Photoredox-catalyzed decarboxylative C(sp3)–C(sp3) coupling

Photoredox-catalyzed decarboxylative C(sp3)–C(sp3) coupling is a family of organic reactions in which a visible-light-excited photocatalyst converts carboxylic acids into alkyl radicals, forming carbon–carbon bonds under mild conditions without organometallic reagents.

Photoredox-catalyzed dehalogenative functionalization of alkyl halides

Photoredox-catalyzed dehalogenative functionalization of alkyl halides is a family of visible-light reactions that turn alkyl halides into carbon radicals for new bonds, replacing toxic tin reagents.

Photoredox-catalyzed hydrogen isotope exchange

Photoredox-catalyzed hydrogen isotope exchange (photoredox HIE) is a set of light-driven methods for replacing hydrogen with deuterium or tritium in organic molecules, first reported by MacMillan in 2017.

Photoredox-catalyzed trifluoromethylation with CF3SO2Cl

A visible-light photoredox method for installing trifluoromethyl groups onto organic molecules using trifluoromethanesulfonyl chloride (CF3SO2Cl), established for arenes and heteroarenes by David MacMillan's group at Princeton in 2011.

Photoredox-enabled Giese addition of redox-active esters

Photoredox-enabled Giese addition of redox-active esters is a visible-light carbon–carbon bond-forming reaction that turns NHPI esters of carboxylic acids into alkyl radicals adding to electron-poor alkenes.

Photoredox-enabled ring contractions and expansions

Light-driven skeletal edits of cyclic molecules where a visible-light-excited photocatalyst generates radical intermediates that shrink or enlarge rings by one or more atoms, first shaped around 2020.