Rhodium(<scp>iii</scp>)-catalyzed asymmetric [4+1] spiroannulations of <i>O</i>-pivaloyl oximes with α-diazo compounds
作者:Lincong Sun、Bingxian Liu、Yanlian Zhao、Junbiao Chang、Lingheng Kong、Fen Wang、Wei-Qiao Deng、Xingwei Li
DOI:10.1039/d1cc02888j
日期:——
Chiral RhIII catalysts can catalyze the asymmetric [4+1] spiroannulation of O-pivaloyl oximes with α-diazo homophthalimides under redox-neutral and acid/base-neutral conditions, leading to formation of chiral spirocyclic imines as a result of C–H activation and N–O cleavage. The reaction proceeded with high efficiency and features broad substrate scope, mild reaction conditions, and high to excellent
Copper(<scp>i</scp>)-catalyzed heteroannulation of [60]fullerene with ketoxime acetates: preparation of novel 1-fulleropyrrolines
作者:Sheng-Peng Jiang、Yi-Tan Su、Kai-Qing Liu、Qing-Hua Wu、Guan-Wu Wang
DOI:10.1039/c5cc01198a
日期:——
A cuprous bromide-catalyzed heteroannulation reaction of [60]fullerene with ketoxime acetates has been exploited to prepare novel 1-fulleropyrrolines through the cleavage of N-O and C-Hbonds and formation of C-C and C-N bonds under thermal conditions. A plausible mechanism for the formation of 1-fulleropyrrolines is proposed on the basis of the experimental results. The electrochemistry of the obtained
dihydrobenzofuran-fused pyridones in moderate to good yields with good functional group compatibility. The reaction likely involves a radical relay annulation, leading to the ring opening of the lactone moiety of the coumarins, and simultaneous formation of three new bonds. The investigation of photoluminescent properties reveals that several obtained compounds may have potential as fluorescent materials.
A useful Cu-catalyzed cycloaddition protocol for the construction of benzene rings has been achieved. The reactions, utilizing readily available oximes and maleimides as starting materials, proceed under mild reaction conditions to generate a series of structurally interesting fused-phthalimides that are difficult to be prepared by conventional methods.
Synthesis of Fused-Pyrazines <i>via</i>
Palladium-Catalyzed Double Benzyl Isocyanide Insertion and Cross-Dehydrogenative Coupling
作者:Gopal Chandru Senadi、Bing-Chun Guo、Yu-Ching Chang、Wan-Ping Hu、Jeh-Jeng Wang
DOI:10.1002/adsc.201701202
日期:2018.2.1
palladium‐catalyzed cascade reaction has been realized for the synthesis of 5H‐pyrrolo[2,3‐b]pyrazines and 5H‐pyrazino[2,3‐b]indoles from benzyl isocyanide by choosing o‐pivaloyloximes or o‐iodoanilines as a suitable substrate. The key steps involved are (i) oxidative addition of palladium through N–O or C–I cleavage; (ii) migratory double isocyanide insertion; and (iii) cross‐dehydrogenativecoupling. Notable
通过选择邻-吡咯并酮肟或邻-碘苯胺,已实现了钯催化的级联反应,可从异氰酸苄酯合成5 H-吡咯并[2,3- b ]吡嗪和5 H-吡嗪并[2,3- b ]吲哚。作为合适的基材。涉及的关键步骤是(i)通过N-O或C-I裂解氧化钯的加成;(ii)迁移性双异氰酸酯插入;(iii)交叉脱氢偶联。显着的特征是良好的官能团耐受性以及三个C–C和一个C–N键的形成。