Organocatalytic Enantioselective Higher-Order Cycloadditions of In Situ Generated Amino Isobenzofulvenes.

Autor: Donslund BS; Department of Chemistry, Aarhus University, Langelandsgade 140, 8000, Aarhus C, Denmark., Monleón A; Department of Chemistry, Aarhus University, Langelandsgade 140, 8000, Aarhus C, Denmark., Palazzo TA; Department of Chemistry, Aarhus University, Langelandsgade 140, 8000, Aarhus C, Denmark., Christensen ML; Department of Chemistry, Aarhus University, Langelandsgade 140, 8000, Aarhus C, Denmark., Dahlgaard A; Department of Chemistry, Aarhus University, Langelandsgade 140, 8000, Aarhus C, Denmark., Erickson JD; Department of Chemistry, Aarhus University, Langelandsgade 140, 8000, Aarhus C, Denmark., Jørgensen KA; Department of Chemistry, Aarhus University, Langelandsgade 140, 8000, Aarhus C, Denmark.
Jazyk: angličtina
Zdroj: Angewandte Chemie (International ed. in English) [Angew Chem Int Ed Engl] 2018 Jan 26; Vol. 57 (5), pp. 1246-1250. Date of Electronic Publication: 2018 Jan 05.
DOI: 10.1002/anie.201710694
Abstrakt: The [8+2] cycloaddition of indene-2-carbaldehydes and nitro olefins is described to provide benzonorbornene scaffolds in a highly peri-, diastereo-, and enantioselective fashion in the presence of a C 2 -symmetric aminocatalyst. This reaction, which proceeds through a transient semi-aromatic amino isobenzofulvene, represents the first example of catalytic formation and transformation of these species. Quantum chemical calculations suggest a kinetically controlled stepwise mechanism where the stereochemistry is determined in the first bond-forming event. Beyond the useful [8+2] cycloadducts, [10+4] cycloadducts have been identified in silico as potential off-pathway intermediates.
(© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)
Databáze: MEDLINE
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