91056-64-3Relevant academic research and scientific papers
Catalytic enantioselective synthesis of α-aminooxy and α-hydroxy ketone using nitrosobenzene
Momiyama, Norie,Yamamoto, Hisashi
, p. 6038 - 6039 (2003)
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
Reactions of Singlet Oxygen with Enol Esters
Wilson, Stephen L.,Schuster, Gary B.
, p. 2056 - 2060 (2007/10/02)
Singlet oxygenation of 1-adamantylideneethyl acetate (4) and 6,6-dimethylcyclohex-1-enyl acetate (7) produces only "ene" reaction products.Photooxygenation of Δ1,6-2-oxabicyclodecen-3-one (9), in contrast, yields ene, acyl-shifted, and cycloaddition products.The product distribution resulting from oxidation of 9 indicates that attack of singlet oxygen (1O2) occurs exclusively on the same side of the double bond as the ester functional group.The bimolecular rate constant for reaction of 9 with 1O2 is found to be ca. 50 times larger than those of 4 and 7.These results are explained most economicaly by invoking the ini tial formation of a perepoxide intermediate.In the case of 9, stabilization of the transition state leading to the perepoxide by interaction of the incoming 1O2 molecule with the ester functionally produces the observed rate enhancement and stereospecificity.
