Enantioselective Heck Arylations of Acyclic Alkenyl Alcohols Using a Redox-Relay Strategy

• Published in: Science (American Association for the Advancement of Science) Vol. 338; no. 6113; pp. 1455 - 1458
• Main Authors: Werner, Erik W., Mei, Tian-Sheng, Burckle, Alexander J., Sigman, Matthew S.
• Format: Journal Article
• Language: English
• Published: Washington, DC American Association for the Advancement of Science 14.12.2012; The American Association for the Advancement of Science
• Subjects: Alcohols; Alcohols - chemistry; Alkenes; Alkenes - chemistry; Aromatic compounds; Biotechnology; Carbon; Carbon-carbon composites; Catalysis; Catalysts; Chemical bonds; Chemistry; Chemistry Techniques, Synthetic; Diazonium Compounds - chemistry; DNA; Exact sciences and technology; General and physical chemistry; Hydrogen atoms; Ketones; Ketones - chemistry; Ligands; Olefins; Oxidation-Reduction; Salts; Science; Stereoisomerism; Strategy; Tetrahedrons; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Unsaturation; Arylation; Arene; Enantioselectivity; Enol; Organic ligand; Heck reaction; Alcohol; Palladium complex; Asymmetric catalysis; Ethylenic compound
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.1229208

Progress in the development of asymmetric Heck couplings of arenes and acyclic olefins has been limited by a tenuous understanding of the factors that dictate selectivity in migratory insertion and β-hydride elimination. On the basis of key mechanistic insight recently garnered in the exploration of selective Heck reactions, we report here an enantioselective variant that delivers β-, γ-, or δ-aryl carbonyl products from acyclic alkenol substrates. The catalyst system imparts notable regioselectivity during migratory insertion and promotes the migration of the alkene's unsaturation toward the alcohol to ultimately form the ketone product. The reaction uses aryldiazonium salts as the arene source, yields enantiomeric products from opposite starting alkene configurations, and uses a readily accessible ligand. The racemic nature of the alkenol substrate does not bias the enantioselection.