Enantioselective Narasaka-Heck cyclizations: synthesis of tetrasubstituted nitrogen-bearing stereocenters.
نویسندگان
چکیده
The first examples of highly enantioselective Narasaka-Heck cyclizations are described. A SPINOL-derived P,N-ligand system enables Pd-catalyzed 5-exo cyclization of a range of oxime esters with sterically diverse trisubstituted alkenes to generate dihydropyrroles containing tetrasubstituted nitrogen-bearing stereocenters in 56 to 86% yield and 90 : 10 to 95 : 5 e.r. These processes are rare examples of reactions that proceed via enantioselective migratory insertion of alkenes into Pd-N bonds, and the first where trisubstituted alkenes are used to generate tetrasubstituted stereocenters with high enantioselectivity.
منابع مشابه
Enantioselective Narasaka–Heck cyclizations: synthesis of tetrasubstituted nitrogen-bearing stereocenters† †Electronic supplementary information (ESI) available: Experimental procedures and characterisation data for all compounds are provided. CCDC 1438659 and 1438660. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c6sc04466b Click here for additional data file. Click here for additional data file.
School of Chemistry, University of Bristol, B bris.ac.uk AstraZeneca, Alderley Park, Maccleseld, C AstraZeneca, Pepparedsleden 1, Mölndal, 4 † Electronic supplementary information ( and characterisation data for all compou 1438660. For ESI and crystallographic dat DOI: 10.1039/c6sc04466b ‡ These authors contributed equally. § Author to whom correspondence shou structures of 3b and Pd[(Sa,S)-L-...
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ورودعنوان ژورنال:
- Chemical science
دوره 8 3 شماره
صفحات -
تاریخ انتشار 2017