Stereoselective Csp<sup>3</sup>-Csp<sup>2</sup>Bond-Forming Reactions by Transition-Metal-Free Reductive Coupling of Cyclic Tosylhydrazones with Boronic Acids
作者:Manuel Plaza、M. Carmen Pérez-Aguilar、Carlos Valdés
DOI:10.1002/chem.201600837
日期:2016.4.25
The reactions between alkenylboronic acids and tosylhydrazones derived from substituted cyclohexanones lead to the construction of disubstituted cyclohexanes with total regio‐ and stereoselectivity. In these transition‐metal‐free processes, a Csp3−Csp2 and Csp3−H bond are formed on the same carbon atom. The stereoselective reaction is general for 2‐, 3‐, and 4‐substituted cyclohexanone tosylhydrazones
烯基硼酸与衍生自取代环己酮的甲苯磺酰nes之间的反应导致构建具有总区域和立体选择性的双取代环己烷。在这些无过渡金属的过程中,Csp 3 -Csp 2和Csp 3 -H键在同一碳原子上形成。立体选择性反应通常适用于2、3和4取代的环己酮甲苯磺酰nes以及2取代的环戊酮。但是,没有观察到无环衍生物的立体选择性。DFT计算模型表明,反应的立体选择性是通过硼酸通过最赤道的轨迹在其最稳定的椅子构象上对重氮环己烷的反应来确定的。