Stereoselective Alkyne-Alkene [2 + 2] Cycloaddition Enabled by Anion Relay Chemistry for Fully C-Substituted
Xiaomeng Gong1, Rui-Peng Li1, Xiangrong Xu1
1School of Pharmacy, and State Key Laboratory of Applied Organic Chemistry, Lanzhou University, Lanzhou 730000, P. R. China.
Abstract:
Cyclobutenes serve as valuable scaffolds in pharmaceutical development, but synthesizing structurally diverse fully C-substituted cyclobutenes remains challenging. Here we report a stereoselective [2 + 2] cycloaddition between alkynyl 1,3-dithianes and cinnamate esters using a catalytic amount of KOtBu. Our approach enables the construction of synthetically challenging tetrasubstituted cyclobutenes via anion relay chemistry (ARC), exhibiting excellent trans-diastereoselectivities (dr > 20:1).
More Related Videos
06:46Facile Preparation of 2Z,4E-Dienamides by the Olefination of Electron-deficient Alkenes with Allyl Acetate
Published on: June 21, 2017
10:17Efficient Construction of Drug-like Bispirocyclic Scaffolds Via Organocatalytic Cycloadditions of α-Imino γ-Lactones and Alkylidene Pyrazolones
Published on: February 7, 2019
Related Concept Videos
Free-Radical Chain Reaction and Polymerization of Alkenes
Preparation of Alkynes: Alkylation Reaction
Alkylation of terminal alkynes with primary alkyl halides in the presence of a strong base like sodium amide is one of the common methods for the synthesis of longer carbon-chain alkynes. For example, treatment of 1-propyne with sodium amide followed by reaction with ethyl bromide yields 2-pentyne.
Cycloaddition Reactions: Overview
Diels–Alder Reaction Forming Cyclic Products: Stereochemistry
Olefin Metathesis Polymerization: Acyclic Diene Metathesis (ADMET)
Similar to cross-metathesis, ADMET also involves the formation of metallacyclobutane intermediate by [2+2] cycloaddition of one of the double bonds of a terminal diene with...
[3,3] Sigmatropic Rearrangement of Allyl Vinyl Ethers: Claisen Rearrangement
