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
precursors in reactions with thioethers under the catalysis of a commercially available Ru(II) complex, from which a variety of sulfimides were synthesized efficiently and mildly. If an allyl group is contained in the thioether precursor, the [2,3]-sigmatropic rearrangement of the sulfimide occurs simultaneously and the N-allyl-N-(thio)amides were obtained as the final products. Preliminary mechanistic studies
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.
Biotinylated Rh(III) Complexes in Engineered Streptavidin for Accelerated Asymmetric C–H Activation
作者:Todd K. Hyster、Livia Knörr、Thomas R. Ward、Tomislav Rovis
DOI:10.1126/science.1226132
日期:2012.10.26
around the metal center. Modifying an achiral ligand to dock in a protein renders catalysis by its rhodium complex asymmetric. Enzymes provide an exquisitely tailored chiral environment to foster high catalytic activities and selectivities, but their native structures are optimized for very specific biochemical transformations. Designing a protein to accommodate a non-native transition metal complex can