Asymmetric Synthesis of Hydrobenzofuranones via Desymmetrization of Cyclohexadienones Using the Intramolecular Stetter Reaction
作者:Qin Liu、Tomislav Rovis
DOI:10.1021/ja058337u
日期:2006.3.1
Dearomatization of phenols followed by oxidation affords cyclohexadienyloxyacetaldehydes, which produce hydrobenzofuranones via asymmetric intramolecular Stetter reaction in good to excellent yield. Quaternary as well as up to three contiguous stereocenters may be formed in good to excellent enantioselectivities and high diastereoselectivities.
Desymmetrization of Cyclohexadienones through Phase-Transfer-Catalyzed Stereoselective Intramolecular Aza-Michael Addition with Chiral Sulfinamide Nucleophiles
This paper reports the desymmetrization of cyclohexadienones through stereoselective intramolecularaza-Michael addition with a tethered chiral sulfinamide nucleophile. The reaction was facilitated by phase-transfer catalysis and produced various nitrogen-containing bicyclic compounds with a yield of up to 93% and a diastereomeric ratio of up to >20:1.
Enantioselective Synthesis of Hydrobenzofuranones Using an Asymmetric Desymmetrizing Intramolecular Stetter Reaction of Cyclohexadienones
作者:Qin Liu、Tomislav Rovis
DOI:10.1021/op600278f
日期:2007.5.1
A series of cyclohexadienones were synthesized by dearomatization of phenols followed by Dess-Martin oxidation. Asymmetric intramolecular Stetter reactions of these substrates provide hydrobenzofuranones in good to excellent yields and excellent stereoselectivities. Up to three stereocenters as well as quaternary stereocenter are formed from polysubstituted substrates. A scale up experiment demonstrates
A modular approach has been developed for an efficient synthesis of an aminal group containing a new tetracyclic framework. The strategy has been devised based on selective hydrogen-bond-guided aza-Michael addition of heteroaromatic amines to cyclohexadienone-aldehydes. The reaction is highly atom economic and practical and involves stereoselective construction of four new C–N bonds and four rings