Amphiphilic reactions by means of exceptionally bulky organoaluminum reagents. Rational approach for obtaining unusual equatorial, anti-Cram, and 1,4 selectivity in carbonyl alkylation
The reaction of α-metalated imines with esters under mild conditions leads to the Schiff base of unsymmetrical 1,3-diketones (enamino ketones) in good yields.
在温和条件下,α-金属化亚胺与酯反应能够以良好产率生成非对称1,3-二酮(烯胺酮)的希夫碱。
Vinylcyclobutanols: A Composite Functional Group?
作者:Barry M. Trost、Deborah W. C. Chen
DOI:10.1021/ja9624432
日期:1996.1.1
probed by the examination of the behavior of vinylcyclobutanols as terminators in cyclization reactions. The substrates were readily available by the addition of vinyllithium reagents bearing acetals as cyclization initiators to cyclobutanone. Bronsted and Lewis acids both promoted cyclization in contrast to vinylcyclopropanolterminators for which Bronsted acids failed. The products are spirocycles consisting
Synthesis of Pyridines and Pyrazines Using an Intramolecular Hydroamination-Based Reaction Sequence
作者:Toni Rizk、Eric J.-F. Bilodeau、André M. Beauchemin
DOI:10.1002/anie.200903922
日期:2009.10.19
A management issue! Various pyridines and pyrazines can be efficiently accessed from simple acyclic precursors using an intramolecularhydroamination/isomerization/aromatization sequence (see scheme). p‐Toluenesulfonic acid (2 mol %) is used to catalyze this novel alkyne annulation, in which the oxime group allows for a subsequent redox‐neutral aromatization step to occur.
Microwave-Assisted Reactions of Schiff Bases with Diethyl Phosphonate in the Presence of CdI2
作者:M. M. Kabachnik、E. V. Zobnina、I. P. Beletskaya
DOI:10.1007/s11178-005-0194-y
日期:2005.4
The reaction of diethyl phosphonate with Schiff bases derived from aldehydes and ketones in the presence of cadmium iodide is strongly accelerated by microwave irradiation, and the corresponding α-aminophosphonates are formed in high yields.
A New, Efficient and Stereoselective Synthesis of Tricyclic and Tetracyclic Compounds by Samarium Diiodide Induced Cyclisations of Naphthyl-Substituted Arylketones—An Easy Access to Steroid-Like Skeletons
we present the application of samariumdiiodide induced cyclisations of naphthyl-substituted ketones towards an easy and stereoselectiveaccess to tri- and tetracyclic-functionalised compounds. Typical naphthalene derivatives were studied to investigate the scope and limitations of this novel cyclisation process. The model substrates studied demonstrate that the samarium ketyl cyclisations are essentially