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Journal articles
Preparation of new axially chiral bridged 2,2′-bipyridines and pyridyl monooxazolines (pymox). Evaluation in copper( i )-catalyzed enantioselective cyclopropanation
Abstract : This work reports the synthesis of new axially chiral bridged 2,2′-bipyridines 1 and pyridylmonooxazolines (pymox) 2. The potential of these new axially chiral N,N-ligands was evaluated in asymmetric catalytic cyclopropanation of styrene derivatives 22a–c with diazoesters 21a,b. While 2,2′-bipyridines 1a–c afforded the corresponding cyclopropanes 23a–f in up to 65% ee, pymoxs 2a–e gave somewhat lower enantioselectivities (up to 53% ee). Both classes of ligands produced trans-cyclopropanes 23a–f as the major isomer, although with modest diasteroselectivities (56 : 44 to 78 : 22). A structure-stereoselectivity relationship study of ligands 1 and 2 identified the chiral biaryl axis as being mostly responsible for the enantioselective performances of these ligands.
https://hal-normandie-univ.archives-ouvertes.fr/hal-02278796
Contributor : Sylvain Oudeyer <>
Submitted on : Wednesday, September 4, 2019 - 4:06:28 PM
Last modification on : Thursday, July 2, 2020 - 3:29:24 AM
Contributor : Sylvain Oudeyer <>
Submitted on : Wednesday, September 4, 2019 - 4:06:28 PM
Last modification on : Thursday, July 2, 2020 - 3:29:24 AM
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