36103-31-8Relevant academic research and scientific papers
Catalytic enantioselective synthesis of α-aminooxy and α-hydroxy ketone using nitrosobenzene
Momiyama, Norie,Yamamoto, Hisashi
, p. 6038 - 6039 (2007/10/03)
The highly enantioselective and O-selective nitroso aldol reaction of tin enolates 2 and nitrosobenzene (1) has been developed with the use of (R)-BINAP-silver complexes as a catalyst. After the various silver salts were surveyed, the AgOTf and the AgClO4 complex were found to be optimal in the O-selective nitroso aldol reaction in both asymmetric induction (up to 97% ee) and regioselection (O/N = >99/1), affording aminooxy ketone 3. The product 3 can be transformed to α-hydroxy ketone 5 without any loss of enantioselectivity. Thus, the method provides an efficient approach to the catalytic enantioselective introduction of oxygen α- to the carbonyl group. Copyright
The photoaddition of 1,3-diketonatoboron difluorides with benzene derivatives
Chow, Yuan L.,Ouyang, Xinxin
, p. 423 - 431 (2007/10/02)
The boron difluoride complexes of 2-acetylcyclohexanone, 2-acetylcyclopentanone, and acetylacetone (abbreviated as ACHBF2, ACPBF2, and AABF2) were irradiated in the presence of benzene to give 1:1 adducts as the primary photoadducts; for certain BF2 complexes, toluene, chlorobenzene, benzonitrile, and methyl benzoate were also used as substrates.The 1,5-diketone photoadducts were assumed to form by a photocycloaddition followed by cyclobutane opening and hydrolysis to give 1,2 adducts.They undergo a variety of secondary thermal reactions, probably acid catalyzed, to give enol ethers, enol acetates, acetophenones, and ketonylacetophenones.The efficiency of these secondary reactions determines the final products.Photoaddition with a monosubstituted benzene preferentially occurs at the 3,4 bond without regioselectivity.Under oxygen, ACHBF2 photolytically reacts with benzene to give a secondary oxidation product of a 10-membered cyclic alkylphenone, which is proven by X-ray crystallographic analysis to have the benzene ring and carbonyl group in orthogonal orientation.It is shown that the singlet excited state ACHBF2 initiates the photoaddition, probably through the formation of the benzene exciplex, which could be detected by its emission.While the Stern-Volmer rates are small, the quantum yield of photoaddition products is as high as 0.12-0.19 under limiting conditions.
