Deuteration Degree‐Controllable Methylation via a Cascade Assembly Strategy using Methylamine‐Water as Methyl Source
作者:Fuhu Guo、Shiquan Shan、Xu Gong、Cancan Dai、Zhengjun Quan、Xiamin Cheng、Xinyuan Fan
DOI:10.1002/chem.202301458
日期:2023.8.10
Methylamine-water system was developed as a new methyl source for the methylation of β-diketones under mild photocatalytic reaction conditions. Degree-controllable deuterated methylation could be easily achieved by using distinct combinations of d-methylamine-D2O system, allowing for the synthesis of deuterium-labelled bioactive molecules with a controllable number ranging from 0 to 3.
Generation and Radical–Radical Cross-Coupling of Alkenyloxy Radical
作者:Yunquan Man、Bo Xu
DOI:10.1021/acs.orglett.4c00627
日期:2024.3.29
the alkene moiety. The direct radical–radical cross-coupling of O radicals is also challenging (limited to N–O bond formation) because of the lack of suitable persistent radical species. This study demonstrated the feasibility of using Breslow intermediate radical (BIR) as a persistent radical to capture unstable π-conjugated O radicals and allow the C–O radical–radical cross-coupling.
烯烃连接的氧自由基很少使用,因为高反应性氧自由基与烯烃部分不相容。由于缺乏合适的持久性自由基种类,O自由基的直接自由基-自由基交叉偶联也具有挑战性(仅限于N-O键的形成)。这项研究证明了使用 Breslow 中间自由基 (BIR) 作为持久自由基来捕获不稳定的 π-共轭 O 自由基并允许 C-O 自由基-自由基交叉偶联的可行性。
N-Heterocyclic Carbene-Catalyzed Cross-Coupling of Aromatic Aldehydes with Activated Alkyl Halides
作者:Mohan Padmanaban、Akkattu T. Biju、Frank Glorius
DOI:10.1021/ol102626p
日期:2011.1.7
N-Heterocyclic carbene-catalyzed umpolung of aldehydes followed by their interception with diarylbromomethanes has been reported. This conceptually novel transition-metal-free cross-coupling of aldehydes with alkyl halides works well at low catalyst loadings and under mild reaction conditions leading to the formation of diaryl acetophenone derivatives in good yields. In addition, a-halo ketones and esters can also be used, as aldehyde reaction partners.