Nucleo-Palladation-Triggering Alkene Functionalization: A Route to γ-Lactones
摘要:
An unprecedented strategy for the highly effective synthesis of gamma-lactones from homoallylic alcohols was achieved by palladium catalysis in one step. The protocol affords aryl, alkyl, and spiro gamma-lactones directly from readily available "homoallylic alcohols in good yields with excellent functional group tolerance and high chemoselectivity under mild conditions.
(HMe2SiCH2)2: A Useful Reagent for B(C6F5)3-Catalyzed Reduction–Lactonization of Keto Acids: Concise Syntheses of (–)-cis-Whisky and (–)-cis-Cognac Lactones
(HMe2SiCH2)2 has been utilized as a useful reagent for B(C6F5)3-catalyzed reduction–lactonization of keto acids to synthesize γ- and δ-lactones. The process led concisely to (–)-cis-whisky and (–)-cis-cognac lactones in respective overall yields of 32% and 36%.
Copper-Catalyzed Intermolecular Oxidative [3 + 2] Cycloaddition between Alkenes and Anhydrides: A New Synthetic Approach to γ-Lactones
作者:Liangbin Huang、Huanfeng Jiang、Chaorong Qi、Xiaohang Liu
DOI:10.1021/ja108073k
日期:2010.12.22
A new copper-catalyzed oxidative [3 + 2] cycloaddition of alkenes with anhydrides using oxygen as the sole oxidant to afford γ-lactones has been developed. This catalyzed cyclization process has a broad substrate scope and affords γ-lactones in good to excellent yields.
γ-Substituted butyrolactones from acrolein and carbonyl compounds
作者:José Barluenga、José R. Fernández、Miguel Yus
DOI:10.1039/c39870001534
日期:——
The lithiation of 3-chloropropanal diethyl acetal (easily prepared fromacrolein) at –78 °C with lithium naphthalenide followed by reaction with various carbonylcompounds, and final oxidation with m-chloroperbenzoic acid leads to γ-substitutedbutyrolactones.
This work provides an in-depth investigation of the Pd(II)-catalyzed oxidative cyclization of various alkenoic acids bearing different tethers between the carboxylic acid moiety and the olefin function, showcasing how different mechanistic pathways (oxypalladation or allylic C-H activation) can be operative. The factors biasing toward one or the other of these reactivities are rationally discussed and compared with our recent studies on the Pd(II)-catalyzed intramolecular amination.
Nucleo-Palladation-Triggering Alkene Functionalization: A Route to γ-Lactones
An unprecedented strategy for the highly effective synthesis of gamma-lactones from homoallylic alcohols was achieved by palladium catalysis in one step. The protocol affords aryl, alkyl, and spiro gamma-lactones directly from readily available "homoallylic alcohols in good yields with excellent functional group tolerance and high chemoselectivity under mild conditions.