Direct Formation of Reactive Alkynyltrichlorotins from 1-Alkynes, SnCl<sub>4</sub>, and Bu<sub>3</sub>N. A Mild Alkynylation Reagent of Aldehydes, Acetals, and Enones
A reagent system of 1-alkyne, SnCl4, and Bu3N alkynylates aldehydes, acetals, and enones under mild reaction conditions giving acetylenic alcohols, acetylenic ethers, and acetylenic ketones, respectively, in high yields. Alkynyltrichlorotins are shown to be the reactive species for these reactions.
One-Pot Synthesis of 1,2-Dihydropyridines: Expanding the Diverse Reactivity of Propargyl Vinyl Ethers
作者:Tobias Harschneck、Stefan F. Kirsch
DOI:10.1021/jo102545m
日期:2011.4.1
The catalyzed synthesis of 1,2-dihydropyridines starting from easily accessible propargyl vinyl ethers was realized. The reaction sequence involving a transition metal-catalyzed propargyl-Claisen rearrangement, a condensation step, and a Brønsted acid-catalyzed heterocyclization furnishes the highly substituted heterocycles in moderate to excellent yields. Additionally, a practical one-pot protocol
Gold catalyzed hydrofluorination of propargyl alcohols promoted by fluorine-hydrogen bonding
作者:Hui Yang、Shaowen Wang、Jie Wang、Xiangsheng Xu、Xiaoqing Li
DOI:10.1039/d3cc02275g
日期:——
The hydroxyl group was discovered to promote gold catalyzed hydrofluorination of alkynes via hydrogen bonding interaction. Based on this strategy, propargyl alcohols could be hydrofluorinated smoothly using Et3N·3HF under acidic additive-free conditions, which provided a straightforward alternative protocol for the synthesis of 3-fluoroallyl alcohols.
Terminal alumination of alkynes by DIBALH or trimethylaluminum can be performed in a simple manner in the presence of a small amount of triethylamine. This new Lewis-base-catalyzed process delivers mixed alkynyldialkylalanes of great interest, without the need of an initial deprotonation step with lithium or sodium derivatives followed by a transmetalation.