I<sub>2</sub>-Mediated Oxidative C–N Bond Formation for Metal-Free One-Pot Synthesis of Di-, Tri-, and Tetrasubstituted Pyrazoles from α,β-Unsaturated Aldehydes/Ketones and Hydrazines
An I2-mediated metal-free oxidative C–N bond formation methodology has been established for the regioselective pyrazole synthesis. This practical and eco-friendly one-pot protocol requires no isolation of the less stable intermediates hydrazones and provides a facile access to a variety of di-, tri-, and tetrasubstituted (aryl, alkyl, and/or vinyl) pyrazoles from readily available α,β-unsaturated aldehydes/ketones
I 2介导的无金属氧化C–N键形成方法已建立用于区域选择性吡唑合成。这种实用且环保的一锅操作方案无需分离不稳定程度较高的中间体s,并易于从容易获得的多种二,三和四取代(芳基,烷基和/或乙烯基)吡唑中分离α,β-不饱和醛/酮和肼盐。
A New Germanium-Based Linker for Solid Phase Synthesis of Aromatics: Synthesis of a Pyrazole Library
作者:Alan C. Spivey、Christopher M. Diaper、Harry Adams、Andrew J. Rudge
DOI:10.1021/jo000401x
日期:2000.8.1
An efficient synthesis of chlorogermane linker 12 is described. Economic introduction of germanium into this linker is accomplished by insertion of dichlorogermylene [from germanium(IV) chloride] into the homobenzylic C-Cl bond of 4-(2-chloroethyl)phenol 1. Using linker 12, transmetalation with lithiated 4-acetophenone, 3-acetophenone, and 4-(4'methoxy)biphenyl followed by Mitsunobu-type coupling to
Compounds of Formula I and pharmaceutically acceptable salts thereof, are capable of blockading voltage-dependent sodium channels and are useful in particular, in treating glaucoma and multiple sclerosis.