Substrate‐Controlled Regioselectivity Switch in a Three‐Component 1,3‐Dipolar Cycloaddition Reaction to Access 3,3′‐Pyrrolidinyl‐Spirooxindoles Derivatives
cycloaddition reaction of isatin-derived azomethine ylides with α-cyano-α,β-unsaturated compounds was developed, which enabled diversity-oriented synthesis of a series of novel and structurally complex 3,3′-pyrrolidinyl-spirooxindoles derivatives containing four contiguous and two quaternary stereogenic centers in high yields (up to 92%) and excellent diastereoselectivities (up to >25:1 dr). The reaction displays
Divergent Synthesis of Highly Substituted Tetrahydroquinolines and Cyclopentenes via Lewis Base Catalyzed Switchable [4 + 2] and [3 + 2] Annulations of MBH-Carbonates with Activated Olefins
A highly selective and divergent synthesis which enabled access to various complex compounds is highly attractive in organic synthesis and medicinal chemistry. Herein, we developed an effective method for divergent synthesis of highly substituted tetrahydroquinolines via Lewis base catalyzed switchable annulations of Morita–Baylis–Hillman carbonates with activated olefins. The reaction displayed switchable
Organocatalytic Domino Reaction of Cyanosulfones: Access to Complex Cyclohexane Systems with Quaternary Carbon Centers
作者:Sundaram Rajkumar、Kenneth Shankland、Jonathan M. Goodman、Alexander J. A. Cobb
DOI:10.1021/ol400356k
日期:2013.3.15
of a bifunctionalthiourea catalyst, a highlystereoselective domino reaction occurs to generate complex cyclohexanes with up to four stereogenic centers, one of which is quaternary in nature. Therefore, it is demonstrated that, like nitro compounds, sulfones can undergo an asymmetric intramolecular conjugate addition to α,β-unsaturated esters in the presence of a bifunctionalorganocatalyst.
Highly efficient and diastereoselective construction of substituted pyrrolidines bearing a quaternary carbon center via 1,3‐dipolar cycloaddition
作者:Kai‐Kai Wang、Yan‐Li Li、Xiao‐Qian Shuai、Rongxiang Chen、Aili Sun、Zhan‐Yong Wang
DOI:10.1002/jhet.4494
日期:2022.9
A general approach to substituted pyrrolidines via [3 + 2] cycloaddition between nonstabilized azomethine ylides and cyanosulfones was developed. The efficient method provides a series of substituted pyrrolidines bearing a quaternary carbon center in high yields (up to 98%) excellent diastereoselectivities (up to >25:1 dr) under ambient reaction conditions.
开发了一种通过不稳定的偶氮甲碱叶立德和氰基砜之间的 [3 + 2] 环加成取代吡咯烷的通用方法。该有效方法提供了一系列带有季碳中心的取代吡咯烷,在环境反应条件下以高产率(高达 98%)优异的非对映选择性(高达 >25:1 dr )。