Photochemical studies on acyclic alkyl aromatic ketones in the solid state: asymmetric induction and increased chemoselectivity

Tetrahedron ◽  
2012 ◽  
Vol 68 (43) ◽  
pp. 8875-8879 ◽  
Author(s):  
Manling Ma ◽  
Wei Feng ◽  
Fang Guo ◽  
Chao Yang ◽  
Wujiong Xia
Keyword(s):  
Solid State ◽  
Asymmetric Induction ◽  
Aromatic Ketones

Photochemistry of 9-methylbicyclo[3.3.1]nonyl aryl ketones — A novel 1,5-disproportionation of 1,4-hydroxy biradicals and asymmetric induction using the solid-state ionic chiral auxiliary method

2005 ◽  
Vol 83 (9) ◽  
pp. 1460-1472 ◽  
Author(s):  
Shuang Chen ◽  
Brian O Patrick ◽  
John R Scheffer
Keyword(s):  
Solid State ◽  
Single Crystal ◽  
Solid State Ionic ◽  
Chiral Auxiliary ◽  
Asymmetric Induction ◽  
X Ray Crystallography ◽  
Aryl Ketones ◽  
Hydroxy Biradicals ◽  
Phenyl Ketones ◽  
State Ionic

A novel 1,5-disproportionation reaction has been discovered for 1,4-hydroxy biradicals derived from the photolysis of 9-methylbicyclo[3.3.1]nonyl phenyl ketones (1), which undergo mainly Yang cyclization both in solution and the solid state. By applying the solid-state ionic chiral auxiliary method of asymmetric synthesis to the Yang cyclization, enantiomeric excesses as high as 95% were achieved at high reaction conversions. The origin of the reaction selectivity is discussed with the help of X-ray crystallography. In addition, the solid-state photoreaction of ketone 1b was found to occur in a single crystal-to-single crystal fashion.Key words: photochemistry, 1,4-hydroxy biradical, disproportionation, asymmetric induction, ionic chiral auxiliary, single crystal-to-single crystal reaction.

Chiral α-hydroxy acid-coadsorbed TiO2 photocatalysts for asymmetric induction in hydrogenation of aromatic ketones

2018 ◽  
Vol 54 (89) ◽  
pp. 12610-12613 ◽  
Author(s):  
Shigeru Kohtani ◽  
Akira Kawashima ◽  
Fumie Masuda ◽  
Momono Sumi ◽  
Yuichi Kitagawa ◽  
...  
Keyword(s):  
Surface Structure ◽  
Crystalline Phase ◽  
Hydroxy Acid ◽  
Asymmetric Induction ◽  
Tio2 Photocatalysts ◽  
Aromatic Ketones ◽  
Structure And Morphology ◽  
Phase Surface

In enantioselective photohydrogenation of aromatic ketones on TiO2, the enantioselectivity is strongly affected by not only chiral reagents but also the crystalline phase, surface structure, and morphology of TiO2.

Asymmetric induction in the solid state photochemistry of an α-mesityl-acetophenone derivative through the use of ionic chiral auxiliaries

1999 ◽  
Vol 40 (50) ◽  
pp. 8733-8736 ◽  
Author(s):  
Eugene Cheung ◽  
Katja Rademacher ◽  
John R. Scheffer ◽  
James Trotter
Keyword(s):  
Solid State ◽  
Asymmetric Induction ◽  
Chiral Auxiliaries

Electrochemical and spectroscopic behavior of trifluoromethylacetophenone in aqueous and micellar medium

1995 ◽  
Vol 73 (9) ◽  
pp. 1488-1496 ◽  
Author(s):  
Elodie Liotier ◽  
Guy Mousset ◽  
Christine Mousty
Keyword(s):  
Electrochemical Behavior ◽  
Ph Dependence ◽  
Asymmetric Induction ◽  
Micellar Medium ◽  
Medium Ph ◽  
Ketone Reduction ◽  
Aromatic Ketones ◽  
Uv Visible ◽  
Chiral Surfactants ◽  
Spectroscopic Behavior

The electrochemical behavior of 4-trifluoromethylacetophenone (TFMA) has been studied in aqueous (2 ≤ pH ≤ 10), micellar, and ethanolic solutions using polarographic techniques. A slow hydration process of the carbonyl group has been observed by means of polarography and UV–visible spectrophotometry. Besides the well-known pH dependence of the electroreduction of aromatic ketones, C—F bond cleavages concomitant to the ketone reduction occur under electrolysis conditions in alkaline medium (pH = 10) at a very negative potential (−1.7 V), leading to the formation of 4-methylacetophenone, which is reduced at this potential with formation of the carbinol and of symmetrical and dissymmetrical pinacols. Finally, the reduction of TFMA has been performed in the presence of chiral surfactants in order to test their ability to induce an asymmetric induction. Keywords: 4-trifluoromethylacetophenone, 4-methylacetophenone, electroreduction, micellar medium, chiral surfactants, hydration, C—F bond fission.

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