Silver(I)-Catalyzed Cascade: Direct Access to Furans from Alkynyloxiranes
摘要:
Functionalized furans are conveniently formed by a new silver(I)-catalyzed reaction of alk-1-ynyl oxiranes in the presence of p-toluenesulfonic acid and methanol. Evidence supported a cascade mechanism.
synthesized through regio- and stereoselective iodo(III)functionalization of alkynes. The combination of chlorobenziodoxole and silver salt has proven to generate a versatile cationic iodine(III) electrophile to activate alkynes and engage various carboxylic acids, triethyl phosphate, and p-toluenesulfonic acid as nucleophiles. The β-iodo(III)enol esters serve as starting materials for the synthesis of multisubstituted
Nickel‐Catalyzed Carbofluoroalkylation of 1,3‐Enynes to Access Structurally Diverse Fluoroalkylated Allenes
作者:Kai‐Fan Zhang、Kang‐Jie Bian、Chao Li、Jie Sheng、Yan Li、Xi‐Sheng Wang
DOI:10.1002/anie.201813184
日期:2019.4
A nickel‐catalyzed 1,4‐carbofluoroalkylation of 1,3‐enynes to access structurally diverse fluoroalkylated allenes has been established. This method has demonstrated high catalytic reactivity, mild reaction conditions, broad substrate scope, and excellent functional‐group tolerance. The key to success is the use of a nickel catalyst to generate different fluoroalkyl radicals from readily available and
Beyond the Limits: Palladium-N-Heterocyclic Carbene-Based Catalytic System Enables Highly Efficient [4+2] Benzannulation Reactions
作者:Olga V. Zatolochnaya、Alexey V. Galenko、Vladimir Gevorgyan
DOI:10.1002/adsc.201100983
日期:2012.4.16
A highlyefficientcatalyticsystem for the palladium‐catalyzed [4+2] benzannulationreaction of enynes and enynophiles has been developed. The use of an N‐heterocyclic carbene‐based palladium precursor allowed us to achieve turnover numbers up to 1800. The new catalyticsystem has enabled an expansion of the scope of the [4+2] homo‐benzannulationreaction.
Remarkably Selective Formation of Allenyl and Dienyl Alcohols via Ni-Catalyzed Coupling Reaction of Conjugated Enyne, Aldehyde, and Organozinc Reagents
conjugated enynes, aldehydes, and organozincreagents to form unsaturated alcohols. Ligand effects dramatically control the regioselectivity in these Ni-catalyzed MCRs, leading to the selective formation of allenyl alcohols and conjugated dienyl alcohols. A nickel catalyst promotes the multi-component reactions (MCRs) of conjugated enynes, aldehydes, and organozincreagents to form unsaturated alcohols
Ni-Catalyzed Three-component Coupling Reaction of Conjugated Enyne, Carbonyls, and Dimethylzinc to Construct Allenyl Alcohols
作者:Yasuyuki Mori、Gen Onodera、Masanari Kimura
DOI:10.1246/cl.130865
日期:2014.1.5
Nickel catalyzes the three-component coupling reaction of dimethylzinc, enyne, and carbonyls to provide tetrasubstituted allenyl alcohols. Diethylzinc and diphenylzinc can participate in similar coupling reactions to provide the corresponding allenyl alcohols in reasonable yields.