183969-43-9Relevant articles and documents
Regiochemistry of mercury(II) oxide oxidation of unsymmetrical N,N-disubstituted hydroxylamines
Ali, Sk. Asrof,Hashmi, S. M. Azhar,Siddiqui, Mohammad N.,Wazeer, Mohammed I. M.
, p. 14917 - 14928 (1996)
Mercury(II) oxide oxidation of N,N-disubstituted hydroxylamines with the α and α' carbon atoms containing one and two hydrogen atoms, respectively, gave aldonitrones in a highly regioselective manner. Removal of the α proton is involved in the rate determining step as shown by primary kinetic isotope effect.
Bicyclic and tricyclic compounds with β-amino alcohol groups as chiral ligands in the enantioselective reaction of diethylzinc with aldehydes
Aurich, Hans Guenter,Biesemeier, Frank,Geiger, Michael,Harms, Klaus
, p. 423 - 434 (2007/10/03)
Reduction of the enantiomerically pure allyloxy esters 9 or ent-9 with DIBAH afforded the corresponding aldehydes which were treated in situ with chiral or achiral hydroxylamines 8 to give nitrones 10. These underwent a spontaneous intramolecular 1,3-dipolar cycloaddition, affording the bicyclic compounds 11 and 12, respectively. In an analogous manner, a mixture of the tricyclic compounds 14 and 15 was prepared. Treatment of compound 16 with cyclohexene oxide afforded a mixture of diastereomers 17 and 18. Diastereomers 14 and 15 as well as 17 and 18 could be separated by chromatography. X-ray analyses of compounds 11Ff, 17, and 11Af · HCI were performed. The bicyclic and tricyclic compounds were used as chiral ligands in the reaction of diethylzinc with aldehydes 19, in particular with benzaldehyde (19a). Using bicyclic compounds with a tertiary β-hydroxyalkyl substituent at the N atom as ligands, ee's in the range of 78 to 95% were found. Whereas for the best ligands 11Ae and Af the enantioselectivity in the reaction of 4-tolualdehyde was only slightly decreased, with the aliphatic aldehydes 19c and d distinctly lower enantioselectivities were determined. VCH Verlagsgesellschaft mbH, 1997.
