β–αPhotoisomerization of Cobaloxime Complexes in the Solid State. 6. Asymmetric Induction Due to Chiral Crystal Environment

1997 ◽  
Vol 70 (10) ◽  
pp. 2417-2423 ◽  
Author(s):  
Tsuneo Koura ◽  
Yuji Ohashi
2005 ◽  
Vol 83 (9) ◽  
pp. 1460-1472 ◽  
Author(s):  
Shuang Chen ◽  
Brian O Patrick ◽  
John R Scheffer

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.


1999 ◽  
Vol 40 (50) ◽  
pp. 8733-8736 ◽  
Author(s):  
Eugene Cheung ◽  
Katja Rademacher ◽  
John R. Scheffer ◽  
James Trotter

Tetrahedron ◽  
2012 ◽  
Vol 68 (43) ◽  
pp. 8875-8879 ◽  
Author(s):  
Manling Ma ◽  
Wei Feng ◽  
Fang Guo ◽  
Chao Yang ◽  
Wujiong Xia

1999 ◽  
Vol 121 (12) ◽  
pp. 2919-2920 ◽  
Author(s):  
Eugene Cheung ◽  
Matthew R. Netherton ◽  
John R. Scheffer ◽  
James Trotter

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