Nickel(II)-Catalyzed [3 + 2] Cycloaddition of Nitrones and Allenoates to Access <i>N</i>-Vinylindoles and <i>N</i>-Vinylpyrroles
作者:Pei-Pei Xu、Jun-Yi Liao、Jia-Jie Zhang、Wei-Min Shi、Cui Liang、Gui-Fa Su、Dong-Liang Mo
DOI:10.1021/acs.orglett.1c02695
日期:2021.10.1
A variety of N-vinylindoles and N-vinylpyrroles were prepared in moderate to good yields through the nickel(II)-catalyzed [3 + 2] cycloaddition of α,β-unsaturated nitrones with allenoates under mild reaction conditions. A rational mechanism for the formation of N-vinylindoles was proposed based on the 18O-labeled experiments and key intermediates detected by high-resolution mass spectrometry trace
在温和的反应条件下,通过镍 (II) 催化的 α,β-不饱和硝酮与烯丙酸酯的 [3 + 2] 环加成反应,以中等至良好的收率制备了多种N-乙烯基吲哚和N-乙烯基吡咯。基于18个O标记实验和高分辨率质谱痕量实验检测到的关键中间体,提出了N-乙烯基吲哚形成的合理机制。本方法突出了镍 (II) 控制的环化、原子经济反应、广泛的底物范围、良好的官能团耐受性和烯胺键的高 Z 立体选择性。
Manganese‐Catalyzed C−H Functionalizations: Hydroarylations and Alkenylations Involving an Unexpected Heteroaryl Shift
作者:Chengming Wang、Ai Wang、Magnus Rueping
DOI:10.1002/anie.201704682
日期:2017.8.7
A manganese-catalyzed regio- and stereoselective hydroarylation of allenes is reported. The C−H functionalization method provides access to various alkenylated indoles in excellent yields. Moreover, a hydroarylation/cyclization cascade involving an unexpected C−N bond cleavage and aryl shift has been developed, which provides a new synthetic approach to substituted pyrroloindolones.
Synthesis of highly substituted oxetanes via [2+2] cycloaddition reactions of allenoates catalyzed by a guanidine Lewis base
作者:Philipp Selig、Aleksej Turočkin、William Raven
DOI:10.1039/c3cc40855h
日期:——
The first synthesis of highly substituted 3-alkyl-oxetan-2-ylidenes from allenoates was developed by using the bicyclic guanidine 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) as an exceptionally active nitrogen Lewis base catalyst.
Enantioselective γ‐Addition of Pyrazole and Imidazole Heterocycles to Allenoates Catalyzed by Chiral Phosphine
作者:Haiyang Wang、Chang Guo
DOI:10.1002/anie.201813381
日期:2019.2.25
catalyze the enantioselective asymmetric γ‐addition of heteroaromatic compounds to allenoates in good yields with high enantiomeric ratios and regioselectivity in the presence of (S)‐BINOL. Both pyrazole and imidazole could be employed in this process. The synthetic value of these γ‐addition products was demonstrated by the preparation of biologically relevant molecules and structural scaffolds. Remarkably
Copper-Catalyzed, C–C Coupling-Based One-Pot Tandem Reactions for the Synthesis of Benzofurans Using <i>o</i>-Iodophenols, Acyl Chlorides, and Phosphorus Ylides
作者:Yunyun Liu、Hang Wang、Jie-Ping Wan
DOI:10.1021/jo5017508
日期:2014.11.7
One-pot reactions involving acyl chlorides, phosphorusylides, and o-iodophenols with copper catalysis have been established for the rapid synthesis of functionalized benzofurans. With all of these easily available and stable reactants, the construction of the target products has been accomplished via tandem transformations involving a key C–C coupling, leading to the formation of one C(sp2)–C bond