Palladium-catalyzed carbocyclization–cross-coupling reactions of two different allenic moieties: synthesis of 3-(buta-1,3-dienyl) carbazoles and mechanistic insights
Highly stereoselective kinetic resolution of α-allenic alcohols: an enzymatic approach
作者:Wenhua Li、Zuming Lin、Long Chen、Xuechao Tian、Yan Wang、Sha-Hua Huang、Ran Hong
DOI:10.1016/j.tetlet.2015.12.098
日期:2016.2
A highly efficient lipase AK-catalyzed direct kinetic resolution of a variety of α-allenic alcohols was developed. With the complementary to previous studies, the current reaction system is effective on a broad range of substituents (R1) at C(1), such as alkyl, aryl, alkenyl, and alkynyl groups. The Jones–Burgess empirical model was modified to interpret the reversed selectivity during the acetylation
with azomethineimines has successfully been developed under mild reaction conditions, affording biologically interesting tetrahydropyrazoloisoquinoline derivatives in high to excellent yields and with excellent stereoselectivity. The reaction follows a tandem [3+2] cycloaddition/allylation/elimination of AcOH pathway. Allenyl carbinol acetates also reacted well with in situ generated azomethine imine
Controlled Heterocyclization/Cross-Coupling Domino Reaction of β,γ-Allendiols and α-Allenic Esters: Method and Mechanistic Insight for the Preparation of Functionalized Buta-1,3-dienyl Dihydropyrans
作者:Benito Alcaide、Pedro Almendros、Teresa Martínez del Campo、M. Teresa Quirós、Elena Soriano、José L. Marco-Contelles
DOI:10.1002/chem.201300774
日期:2013.10.11
Starting from β,γ‐allendiols and α‐allenic acetates, a chemo‐ and regiocontrolled palladium‐catalyzed methodology has provided access to enantiopure 3,6‐dihydropyrans that bear a buta‐1,3‐dienyl moiety. Thus, it has been demonstrated for the first time that the preparation of six‐membered heterocycles through cross‐coupling reactions of two different allenes can be accomplished. These heterocycliz
An efficient Pd/Cu co-catalyzed dynamic kinetic allenylic alkylation of racemic allenylic acetates with aldimine esters has been developed. Various allenes bearing α,β-adjacent centralchiralities were obtained with excellent stereoselectivities. The easy interconversion between the uncommon η3-butadienyl palladium intermediates featuring a weak C=C/Pd coordination bond and a stable Csp2−Pd bond is