Stereoselective synthesis of substituted 1,2-ethylenediaziridines and their use as ligands in palladium-catalyzed asymmetric allylic alkylation

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• 作者：Andrea Gual ; i ; Francesco Manoni ; Magda Monari ; Diego Savoia
• 关键词：Asymmetric allylic alkylation ; Aziridine ; Diastereoselective organometallic reaction ; Oxazine ; Palladium
• 刊名：Tetrahedron
• 出版年：2010
• 出版时间：16 January 2010
• 年：2010
• 卷：66
• 期：3
• 页码：715-720
• 全文大小：432 K

文摘

The double addition of organometallic reagents to fused oxazino-oxazines prepared from glyoxal and (S)-phenylglycinol afforded C₂- or C₁-symmetric 1,2-ethylenebis(β-aminoalcohols), depending on the nature of the organometallic reagent. This route was modified by the use of (S)-valinol and phenylglyoxal as starting materials, and by reduction of the oxazino-oxazines by diborane. Cyclization of the β-aminoalcohol moieties gave 1,2-ethylenediaziridines bearing one substituent/stereocenter on the ring carbon and one, two or no substituents/stereocenters in the ethylene tether. These bis(aziridines) were used as ligands in the Pd-catalyzed allylic alkylation of dimethyl malonate. It was established that the substituent(s) in the carbon tether and the configuration of the corresponding stereocenters have limited influence on the enantioselectivity.