145642-47-3Relevant academic research and scientific papers
Copper-Catalyzed Enantioselective Radical 1,4-Difunctionalization of 1,3-Enynes
Zeng, Yuehua,Chiou, Mong-Feng,Zhu, Xiaotao,Cao, Jie,Lv, Daqi,Jian, Wujun,Li, Yajun,Zhang, Xinhao,Bao, Hongli
, p. 18014 - 18021 (2020)
Chiral allenes are important structural motifs frequently found in natural products, pharmaceuticals, and other organic compounds. Asymmetric 1,4-difunctionalization of 1,3-enynes is a promising strategy to construct axial chirality and produce substituted chiral allenes from achiral substrates. However, the previous state of the art in 1,4-difunctionalization of 1,3-enynes focused on the allenyl anion pathway. Because of this, only electrophiles can be introduced into the allene backbones in the second functionalization step, consequently limiting the reaction and allene product types. The development of asymmetric 1,4-difunctionalization of 1,3-enynes via a radical pathway would complement previous methods and support expansion of the toolbox for the synthesis of asymmetric allenes. Herein, we report the first radical enantioselective allene formation via a group transfer pathway in the context of copper-catalyzed radical 1,4-difunctionalization of 1,3-enynes. This method addresses a longstanding unsolved problem in asymmetric radical chemistry, provides an important strategy for stereocontrol with free allenyl radicals, and offers a novel approach to the valuable, but previously inaccessible, chiral allenes. This work should shed light on asymmetric radical reactions and may lead to other enantioselective group transfer reactions.
One-pot conversion of terminal alkynes into gem-disubstituted-alkenes
Luo, Fen-Tair,Fwu, Shiang-Long,Huang, Wen-Shu
, p. 6839 - 6840 (1992)
A one-pot reaction of terminal alkynes with in situ generated hydrogen iodide and organozinc compounds in the presence of Pd(PPh3)4 provided a simple and useful method for the preparation of gem-disubstituted-alkenes.
N-Heterocyclic Carbene-Catalyzed 1,4-Alkylacylation of 1,3-Enynes
Cai, Yuxing,Chen, Jiean,Huang, Yong
, p. 9251 - 9255 (2021/11/30)
The radical relay coupling reaction recently emerged as a powerful synthetic strategy for producing tetrasubstituted allenes. However, bond-forming processes involving the allenyl radical intermediate are mostly limited to those promoted by transition metals. In this report, we describe that a ketyl radical generated from single-electron oxidation of the Breslow intermediate is an excellent coupling partner of allenyl radicals. An organocatalytic 1,4-alkylacylation of 1,3-enynes occurred smoothly in the presence of an aldehyde, a radical precursor, and an N-heterocyclic carbene catalyst. This transformation showed remarkable tolerance to both aromatic and aliphatic aldehydes, enyne substitution, and diversified radical precursors.
Highly Regio- and Stereoselective Ni-Catalyzed Hydrocyanation of 1,3-Enynes
Sun, Feilong,Ni, Jie,Cheng, Gui-Juan,Fang, Xianjie
, p. 5956 - 5960 (2020/05/08)
A highly regio- and stereoselective hydrocyanation of 1,3-enynes was implemented by nickel/diphosphine catalysts. A wide range of highly regio- and stereoselective alkenyl nitriles were efficiently prepared. In this transformation, both the tethered alken
Copper-Catalyzed Radical 1,4-Difunctionalization of 1,3-Enynes with Alkyl Diacyl Peroxides and N-Fluorobenzenesulfonimide
Zhu, Xiaotao,Deng, Weili,Chiou, Mong-Feng,Ye, Changqing,Jian, Wujun,Zeng, Yuehua,Jiao, Yihang,Ge, Liang,Li, Yajun,Zhang, Xinhao,Bao, Hongli
, p. 548 - 559 (2019/01/04)
Many reactions involving allenyl ion species have been studied, but reactions involving allenyl radicals are less well understood, perhaps because of the inconvenience associated with the generation of short-lived allenyl radicals. We describe here a versatile method for the generation of allenyl radicals and their previously unreported applications in the intermolecular 1,4-carbocyanation and 1,4-sulfimidocyanation of 1,3-enynes. With the assistance of the trifunctional reagents, alkyl diacyl peroxides or N-fluorobenzenesulfonimide, a range of synthetically challenging multisubstituted allenes can be prepared with high regioselectivity. These multisubstituted allenes can be easily transformed into synthetically useful structures such as fluorinated vinyl cyanides, lactones, functionalized allenyl amides, 1-aminonaphthalenes, and pyridin-2(1H)-ones, and several novel transformations are reported. The results of radical scavenger and radical clock experiments are consistent with the proposed allenyl radical pathway. Density functional theory (DFT) and IR spectroscopy studies suggest the formation of an isocyanocopper(II) species in the ligand exchange step. On the basis of the results of IR, DFT, and diastereoselectivity studies, an isocyanocopper(II)/copper(I) catalytic cycle is proposed, which differs from the previously considered Cu(III) mechanism in cyanation reactions.
Ultrasound-assisted synthesis of functionalized 1,3-enynes by palladium-catalyzed cross-coupling reaction of α-styrylbutyltelluride with alkynyltrifluoroborate salts
Singh, Fateh Veer,Weber, Minéia,Guadagnin, Rafael Carlos,Stefani, Hélio A.
experimental part, p. 1889 - 1893 (2009/04/07)
An ultrasound-assisted synthesis of functionalized 1,3-enyne scaffolds is described and illustrated by palladium-catalyzed cross-coupling of potassium alkynyltrifluoroborate salts and α-styrylbutyltellurides. This procedure offers easy access to 1,3-enyne
