Regioselective Thermal [3+2]‐Dipolar Cycloadditions of α‐Diazoacetates with
<i>α</i>
‐Sulfenyl/Sulfinyl/Sulfonyl‐
<i>β</i>
‐Chloroacrylamide Derivatives to Form Densely Functionalised Pyrazoles
作者:Aaran J. Flynn、Alan Ford、U. B. Rao Khandavilli、Simon E. Lawrence、Anita R. Maguire
DOI:10.1002/ejoc.201900494
日期:2019.9
Highly regioselective synthetic methodology leading to densely functionalised C(3), C(4) and C(5) substituted pyrazoles via thermal [3+2]‐dipolar cycloaddition, of α‐diazoacetates and α‐thio‐β‐chloroacrylamides, at the sulfide, sulfoxide and sulfone levels of oxidation, is described. This method allows access to C(4)‐sulfenyl or sulfonyl pyrazoles, through migration of the sulfur substituent at the
高度区域选择性的合成方法,通过α-重氮乙酸酯和α-硫代-β-氯丙烯酰胺的热[3 + 2]-偶极环加成反应,导致密集官能化的C(3),C(4)和C(5)取代的吡唑描述了硫化物,亚砜和砜的氧化程度。该方法允许通过硫取代基在硫化物和砜氧化水平的迁移而获得C(4)-亚磺酰基或磺酰基吡唑,同时观察到亚磺酰基的消除导致3,5-二取代的吡唑。