Rational Tuning Chelate Size of Bis-Oxazoline Ligands to Improve Enantioselectivity in the Asymmetric Aziridination of Chalcones
作者:Ma、Da-Ming Du、Xu
DOI:10.1021/jo051765y
日期:2005.11.1
Chalcones were asymmetrically aziridinated with [N-(p-toluenesulfonyl)imino]phenyliodinane (PhINTs) as a nitrene source under catalysis of CuOTf and a series of cyclohexane-linked bis-oxazolines (cHBOXes), which are chelate size rationally tuned bis-oxazolines. The results indicate that highly enantioselective aziridination of chalcones with up to >99% ee have been achieved under catalysis of (S,S)-1
The intramolecular cooperative reactions of 1,2-bis(diazoketone)s initiated by the Wolff rearrangement of alpha-diazoketones have been investigated. Under thermal conditions, 1,2-bis(diazoketone)s are efficiently transformed into 2-cyclopenten-1-one derivatives with complete stereospecificity. Thus, a most extraordinary result is reported, that trans-hydro-2-inden-1-ones (1-3) were synthesized for the first time from trans-1,2-bis(diazoketone)s (5, 11, and 12), respectively. The unprecedented trans-hydroindenone structure was confirmed by X-ray analysis of 3 as well as H-1 NMR analysis and was supported by ab initio molecular orbital calculations. The same reactions were also carried out under photochemical conditions and were applied to 1,3-bis(diazoketone)s, giving 2-cyclohexen-1-one derivatives.
DERVAN P. B.; JONES C. R., J. ORG. CHEM., 1979, 44, NO 13, 2116-2122
作者:DERVAN P. B.、 JONES C. R.
DOI:——
日期:——
Novel intermediates for preparing guanidine derivatives, their preparation and use