Nitrogenous Educts through Oxidative Amidation of Phenols: The Bimolecular Reaction
作者:Sylvain Canesi、Denis Bouchu、Marco A. Ciufolini
DOI:10.1021/ol048094v
日期:2005.1.1
[Reaction: see text] The elusive oxidative amidation of phenols to 4-aza-substituted dienones in the bimolecular mode may be achieved by treatment with iodobenzene diacetate ("DIB") in a mixture of hexafluoro-2-propanol and acetonitrile.
Enantioselective synthesis of hindered cyclic dialkyl ethers via catalytic oxa-Michael/Michael desymmetrization
作者:Michael T. Corbett、Jeffrey S. Johnson
DOI:10.1039/c3sc51022k
日期:——
An asymmetricoxa-Michael/Michael cascade reaction of p-quinols and alpha,beta-unsaturated aldehydes provides access to hindered dialkyl ethers. A highly enantioselective oxa-Michael addition of a tertiary alcohol precedes an intramolecularcyclohexadienone desymmetrization, which allows for the concomitant formation of four contiguous stereocenters in a single step. The highly functionalized bicyclic
Teaming up: The title reaction has been developed to deliver the product α‐alkylidene‐γ‐butyrolactones as single diastereomers with up to 98 % ee (see scheme; Ts=4‐toluenesulfonyl). The enantioselective process is catalyzed by 1, which contains both Lewis base and Brønsted acid moieties.
The acid–base organocatalyzed intramolecularRauhut–Currier (RC) reaction of the dienone enolates has been developed. The enantioselective RC process produces the highly functionalized α-methylidene-γ-butyrolactones as a single diastereomer with up to 98% ee.
作者:Kevin M. Jones、Tim Hillringhaus、Martin Klussmann
DOI:10.1016/j.tetlet.2013.04.064
日期:2013.6
A method for the preparation of oxygen containing spirocycles using singlet oxygen is reported. A series of phenols were converted into the corresponding peroxy-cyclohexadienone derivatives by irradiation with visible light in the presence of a sensitizer and oxygen. The resulting peroxides could be converted into ether and lactone spirocycles in one or two steps. The synthesis of the oxaspirocycles from the phenols can also be performed in a one-pot fashion, avoiding the isolation of the peroxide intermediates. (C) 2013 Elsevier Ltd. All rights reserved.