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ABSTRACT: The immobilization of [Rh(2) (S-PTTL)(S-TCPTTL)(3) ] (PTTL = N-phthaloyl-tert-leucinate, TCPTTL=N-tetrachlorophthaloyl-tert-leucinate) has been accomplished by copolymerization of the Rh(II) -complex-containing monomer with 2-(trifluoromethyl)styrene and a flexible cross-linker. The immobilized catalyst promoted intermolecular carbonyl ylide cycloaddition reactions in CF(3) C(6) H(5) under continuous flow conditions, where high yields as well as high levels of enantioselectivity and turnover number were achieved.
Chemistry 11/2011; 17(50):13992-8. · 5.93 Impact Factor
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Angewandte Chemie International Edition 06/2011; 50(30):6803-8. · 13.45 Impact Factor
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Annalen der Chemie und Pharmacie 10/2010; 2010(35):6850 - 6854. · 3.10 Impact Factor
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Angewandte Chemie International Edition 09/2010; 49(39):6979-83. · 13.45 Impact Factor
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ABSTRACT: The reaction of a six-membered cyclic formyl-carbonyl ylide derived from alpha-diazo-beta-ketoester with phenylacetylene derivatives under the catalysis of dirhodium(II) tetrakis[N-tetrachlorophthaloyl-(S)-tert-leucinate], Rh(2)(S-TCPTTL)(4), provides cycloadducts containing an 8-oxabicyclo[3.2.1]octane ring system in up to 97% ee. This represents the first example of an enantioselective 1,3-dipolar cycloaddition of a cyclic formyl-carbonyl ylide. Using this catalytic process, an asymmetric synthesis of endo-6-aryl-8-oxabicyclo[3.2.1]oct-3-en-2-one natural product 1 from Ligusticum chuanxing Hort. has been achieved.
The Journal of Organic Chemistry 09/2010; 75(17):6039-42. · 4.45 Impact Factor