Rhodium(III)-Catalyzed C–H Activation and Annulation with 1-Alkynylphosphine Sulfides: A Mild and Regioselective Access for the Synthesis of Bulky Phosphine Ligands
作者:Bin Li、Jie Yang、Hong Xu、Haibin Song、Baiquan Wang
DOI:10.1021/acs.joc.5b02265
日期:2015.12.18
We reported herein rhodium(III)-catalyzed C–H activation and annulation reactions for the synthesis of bulky phosphine ligands by using 1-alkynylphosphine sulfides as key starting materials. In the presence of [Cp*RhCl2]2 (5 mol %) and CsOAc (2.0 equiv), various N-(pivaloyloxy)benzamides (3.0 equiv) could react smoothly with 1-alkynylphosphine sulfides at 40 °C in MeOH/CF3CH2OH cosolvent without external
Rhodium-Catalyzed CH Alkynylation of Arenes at Room Temperature
作者:Chao Feng、Teck-Peng Loh
DOI:10.1002/anie.201309198
日期:2014.3.3
The rhodium(III)‐catalyzed ortho CH alkynylation of non‐electronically activated arenes is disclosed. This process features a straightforward and highly effective protocol for the synthesis of functionalized alkynes and represents the first example of merging a hypervalent iodine reagent with rhodium(III) catalysis. Notably, this reaction proceeds at room temperature, tolerates a variety of functional
[4+2] or [4+1] Annulation: Changing the Reaction Pathway of a Rhodium-Catalyzed Process by Tuning the Cp Ligand
作者:Seung Youn Hong、Jisu Jeong、Sukbok Chang
DOI:10.1002/anie.201612559
日期:2017.2.20
A change in reaction pathway was achieved for the first time by tuning the cyclopentadienyl (Cp) ligand used for the rhodium‐catalyzed cyclization of benzamides with conjugated enynones. Depending on the Cp ligand, the reaction pathway switched between [4+2] and [4+1] annulation. Electronic effects turned out to be crucial for the product distribution. The dichotomy was attributed to the alteration
Fluorine Effects on Group Migration via a Rhodium(V) Nitrenoid Intermediate
作者:Cheng-Qiang Wang、Yu Zhang、Chao Feng
DOI:10.1002/anie.201708505
日期:2017.11.20
alkynes with N-pivaloyloxy aryl amides enabled the efficient regiospecificsynthesis of difluorinated 2-alkenyl aniline derivatives (see scheme). The fluorine substituents in the alkyne substrates diverted the course of the reaction from the conventional annulation pathway to promote the hydroarylation process involving Lossen rearrangement.
Ligand design for Rh(<scp>iii</scp>)-catalyzed C–H activation: an unsymmetrical cyclopentadienyl group enables a regioselective synthesis of dihydroisoquinolones
作者:Todd K. Hyster、Derek M. Dalton、Tomislav Rovis
DOI:10.1039/c4sc02590c
日期:——
A modified cyclopentadienyl ligand greatly improves regioselectivity in Rh(iii) catalyzed alkene insertion/C–H activation.