Ligand- and Brønsted acid/base-switchable reaction pathways in gold( i )-catalyzed cycloisomerizations of allenoic acids
- 17 February 2015
- journal article
- research article
- Published by Royal Society of Chemistry (RSC) in Organic & Biomolecular Chemistry
- Vol. 13 (13) , 3936-3949
Abstract
Gold-promoted cyclizations of 2,2-diaryl substituted γ-allenoic acids were found to give three isomeric lactone products, each of which could be obtained selectively by exploiting Brønsted acid/base and ligand effects. Simple 5-exo-trig cyclization products were favored by strong donor ligands or base additives, whereas weak donor ligands and a Brønsted acid additive gave isomeric enelactones resulting from double bond migration. Further optimization afforded a class of medicinally relevant bridged tricyclic lactones via a tandem hydroacyloxylation/hydroarylation process. Kinetic studies and control experiments indicated that the initial 5-exo-trig cyclization product serves as a branch point for further isomerization to the other lactone products via cooperative gold(I)/Brønsted acid catalysis.Keywords
Funding Information
- Division of Chemistry (CHE-1214066)
- Division of Chemistry (CHE-1360610)
This publication has 120 references indexed in Scilit:
- On the Silver Effect and the Formation of Chloride-Bridged Digold ComplexesOrganic Letters, 2013
- Gold and BINOL-Phosphoric Acid Catalyzed Enantioselective Hydroamination/N-Sulfonyliminium Cyclization CascadeOrganic Letters, 2013
- Gold‐Catalyzed Functionalization of Unactivated C(sp3)-H Bonds by Hydride Transfer Facilitated by AlkynylspirocyclopropanesAngewandte Chemie International Edition, 2012
- Regio‐ and Enantioselective Hydroamination of Dienes by Gold(I)/Menthol Cooperative CatalysisAngewandte Chemie International Edition, 2011
- Chiral Brønsted Acid from a Cationic Gold(I) Complex: Catalytic Enantioselective Protonation of Silyl Enol Ethers of KetonesJournal of the American Chemical Society, 2011
- Synthesis of a Simplified Version of Stable Bulky and Rigid Cyclic (Alkyl)(amino)carbenes, and Catalytic Activity of the Ensuing Gold(I) Complex in the Three-Component Preparation of 1,2-Dihydroquinoline DerivativesJournal of the American Chemical Society, 2009
- Ligand-Controlled Access to [4 + 2] and [4 + 3] Cycloadditions in Gold-Catalyzed Reactions of Allene-DienesJournal of the American Chemical Society, 2009
- An Expeditious Synthesis of Bruguierol AThe Journal of Organic Chemistry, 2008
- Mechanistic Insights into the Gold-Catalyzed Cycloisomerization of Bromoallenyl Ketones: Ligand-Controlled RegioselectivityJournal of the American Chemical Society, 2008
- Gold(I)-Catalyzed Intramolecular Hydroarylation of AllenesThe Journal of Organic Chemistry, 2008