title: Concise, Enantioselective, and Versatile Synthesis of (-)-Englerin A Based on a Platinum-Catalyzed [4C+3C] Cycloaddition of Allenedienes.
abstract: A practical synthesis of (-)-englerin A was accomplished in 17 steps and 11 % global yield from commercially available achiral precursors. The key step consists of a platinum-catalyzed [4C+3C] allenediene cycloaddition that directly delivers the trans-fused guaiane skeleton with complete diastereoselectivity. The high enantioselectivity (99 % ee) stems from an asymmetric ruthenium-catalyzed transfer hydrogenation of a readily assembled diene-ynone. The synthesis also features a highly stereoselective oxygenation, and a late-stage cuprate alkylation that enables the preparation of previously inaccessible structural analogues.
authors.affiliation: Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CIQUS) and Departamento de Química Orgánica, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, Spain.
authors.forename: Ronald
authors.initials: R
authors.lastname: Nelson
authors.affiliation: Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CIQUS) and Departamento de Química Orgánica, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, Spain.
authors.forename: Moisés
authors.identifier: 0000-0001-8093-2454
authors.initials: M
authors.lastname: Gulías
authors.affiliation: Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CIQUS) and Departamento de Química Orgánica, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, Spain.
authors.forename: José L
authors.identifier: 0000-0002-7789-700X
authors.initials: JL
authors.lastname: Mascareñas
authors.affiliation: Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CIQUS) and Departamento de Química Orgánica, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, Spain. fernando.lopez@csic.es.|Instituto de Química Orgánica General (CSIC), Juan de la Cierva, 3, 28006, Madrid, Spain. fernando.lopez@csic.es.
authors.forename: Fernando
authors.identifier: 0000-0002-0235-6858
authors.initials: F
authors.lastname: López
keywords: allenes; asymmetric catalysis; cycloaddition; guaiane natural products; total synthesis