Triple CH functionalization: Palladium‐catalyzed synthesis of benzofurans and coumarins by reacting phenols and unactivated olefins is described. The reaction comprises sequential CH functionalization and shows diverse functional group compatibility. Preliminary mechanistic studies shed light into the possible mechanisms.
Metal-free visible-light-initiated direct C3 alkylation of quinoxalin-2(1<i>H</i>)-ones and coumarins with unactivated alkyl iodides
作者:Jun Sun、Hua Yang、Bo Zhang
DOI:10.1039/d1gc03992j
日期:——
visible-light-promoted direct C3 alkylation of quinoxalin-2(1H)-ones and coumarinsusing readily accessible unactivated alkyl iodides as alkylation reagents. By applying this new approach, a broad range of valuable 3-alkylated quinoxalin-2(1H)-ones and coumarins (55 examples) can be facilely obtained at room temperature, thus showing the wide utility of this protocol. Notably, this practical reaction occurs under
我们首次报告了使用容易获得的未活化烷基碘作为烷基化试剂对喹喔啉-2(1 H )-酮和香豆素进行可见光促进的直接 C3 烷基化。通过应用这种新方法,可以在室温下轻松获得各种有价值的 3-烷基化 quinoxalin-2(1 H )-ones 和香豆素 (55 个例子),从而显示了该协议的广泛实用性。值得注意的是,这种实际反应发生在无金属和无外部光催化剂的条件下,表现出广泛的底物范围和高官能团耐受性。
Visible Light‐Induced Regioselective Decarboxylative Alkylation of the C(
<i>sp</i>
<sup>2</sup>
)−H Bonds of Non‐Aromatic Heterocycles
heterocycles has been realized via C(sp3)‐centered radical C(sp2)−C(sp3) bond formation under oxidant‐free conditions at room temperature. This reaction readily incorporates various functional alkyl groups into heterocyclic compounds without observation of any alkyl radicalrearrangement and represents a mild and general tool for the preparation of valuable alkyl group‐functionalized heterocyclic compounds.
Visible-Light-Induced Regioselective Alkylation of Coumarins via Decarboxylative Coupling with <i>N</i>-Hydroxyphthalimide Esters
作者:Can Jin、Zhiyang Yan、Bin Sun、Jin Yang
DOI:10.1021/acs.orglett.9b00327
日期:2019.4.5
An efficient photocatalytic decarboxylative 3-position alkylation of coumarins by using alkyl N-hydroxyphthalimide esters as alkylationreagents has been developed. A variety of NHP esters derived from aliphatic carboxylicacids (primary, secondary, and tertiary) has been proved to be tolerated for this decarboxylation process, affording a broad scope of 3-alkylated coumarin derivatives in moderate
A facile iron-catalyzed decarboxylative radical coupling of alkyl diacyl peroxides with coumarins or chromones has been developed, affording a highly efficient approach to synthesize a variety of α-alkylated coumarins and β-alkylated chromones. The reaction proceeded smoothly without adding any ligand or additive and provided the corresponding products containing a wide scope of functional groups in