Radical Carbonylation under Low
<scp>CO</scp>
Pressure: Synthesis of Esters from Activated Alkylamines at Transition
<scp>Metal‐Free</scp>
Conditions
作者:Fengqian Zhao、Han‐Jun Ai、Xiao‐Feng Wu
DOI:10.1002/cjoc.202000624
日期:2021.4
HighCOpressure (> 40 bar) is usually needed in radical carbonylation reactions in the absence of metal catalyst. In this communication, we developed a transition‐metal‐free radical carbonylation of activated alkylamines with phenols and alcohols under low COpressure (1—6 bar). Various esters were obtained in moderate to excellent yields under simple reaction conditions with good functional group
Dearomatization‐Enabled Visible‐Light‐Induced 1,2‐Alkylsulfonylation of Alkenes Using Sodium Sulfinates and Pyridinium Salts
作者:Yuan Yang、Chong‐Hui Xu、Fan Teng、Jin‐Heng Li
DOI:10.1002/adsc.202000457
日期:2020.8.19
We demonstrate a three‐component 1,2‐alkylsulfonylation of alkenes using sodium sulfinates and pyridiniumsalts through visible light photoredox catalysis, wherein heteroarenium salts are harnessed as radical acceptors via dearomatization. This reaction allows the simultaneous incorporation of sulfonyl and 1,4‐dihydropyridine groups across the C=C bonds to access various sulfonyl‐containing 1,4‐dihydropyridine
Visible light photoredox alkylazidation of alkenes with sodium azide and heteroarenium salts: entry to azido-containing 1,4-dihydropyridines
作者:Yuan Yang、Chong-Hui Xu、Zhi-Qiang Xiong、Jin-Heng Li
DOI:10.1039/d0cc03235b
日期:——
A three-component alkene alkylazidation using sodium azide as the azido resource and heteroarenium salts as functionalized alkyl reagents for producing highly valuable 2-azido-1-(1,4-dihydropyridin-4-yl)-ethanes is described. This reaction allows the incorporation of both an azido group and a 1,4-dihydropyridin-4-yl group across CC bonds to construct two new bonds in a single reaction step, and represents
Continuous-Flow Synthesis of Pyrylium Tetrafluoroborates: Application to Synthesis of Katritzky Salts and Photoinduced Cationic RAFT Polymerization
作者:Carlo Sambiagio、Matteo Ferrari、Koen van Beurden、Nicola della Ca’、Jack van Schijndel、Timothy Noël
DOI:10.1021/acs.orglett.1c00178
日期:2021.3.19
Katritzky salts have emerged as effective alkyl radical sources upon metal- or photocatalysis. These are typically prepared from the corresponding triarylpyrylium ions, in turn an important class of photocatalysts for smallmoleculessynthesis and photopolymerization. Here, a flow method for the rapid synthesis of both pyrylium and Katrizky salts in a telescoped fashion is reported. Moreover, several
Engaging Alkenes and Alkynes in Deaminative Alkyl–Alkyl and Alkyl–Vinyl Cross-Couplings of Alkylpyridinium Salts
作者:Kristen M. Baker、Diana Lucas Baca、Shane Plunkett、Mitchell E. Daneker、Mary P. Watson
DOI:10.1021/acs.orglett.9b03899
日期:2019.12.6
An alkyl-alkyl cross-coupling of Katritzky alkylpyridinium salts and organoboranes, formed in situ via hydroboration of alkenes, has been developed. This method utilizes the abundance of both alkyl amine precursors and alkenes to form C(sp3)-C(sp3) bonds. This strategy is also effective with alkynes, enabling a C(sp3)-C(sp2) cross-coupling. Under these mild conditions, a broad range of functional groups