Enantioselective Copper-Catalyzed Oxy-Alkynylation of Diazo Compounds
作者:Durga Prasad Hari、Jerome Waser
DOI:10.1021/jacs.7b04756
日期:2017.6.28
Enantioselective catalytic methods allowing the addition of both a nucleophile and an electrophile onto diazocompounds give a fast access into important building blocks. Herein, we report the highly enantioselective oxyalkynylation of diazocompounds using ethynylbenziodoxol-(on)e reagents and a simple copper bisoxazoline catalyst. The obtained α-benzoyloxy propargylic esters are useful building blocks
Ethynylbenziodazolones (EBZ) as Electrophilic Alkynylation Reagents for the Highly Enantioselective Copper‐Catalyzed Oxyalkynylation of Diazo Compounds
radicals and nucleophiles, yet they present limited possibilities for further structure and reactivity modification. Herein, the first synthesis is reported for the corresponding ethynylbenziodazolone (EBZ) reagents, in which the oxygen atom in the iodoheterocycle is replaced by a nitrogen atom. The substituent on the nitrogen enables further fine‐tuning of the reagent structure and reactivity. EBZ reagents
Iron-catalyzed [3 + 2]-cycloaddition of <i>in situ</i> generated <i>N</i>-ylides with alkynes or olefins: access to multi-substituted/polycyclic pyrrole derivatives
An iron-catalyzed one-pot three-componentreaction of 1-substituted benzimidazoles with diazoacetates and electron-deficient alkynes or alkenes has been reported. Mechanistically, the reaction goes through a 1,3-dipolar cycloaddition of catalytically generated benzimidazolium N-ylides with various activated alkynes or alkenes, leading to multi-substituted and polycyclic fused pyrrole derivatives, respectively
A rhodium-catalysed three-component reaction to access C1-substituted tetrahydroisoquinolines
作者:Dan Zhang、Junwen Liu、Zhenghui Kang、Huang Qiu、Wenhao Hu
DOI:10.1039/c9ob02303h
日期:——
rhodium-catalyzed three-componentreaction of diazocompounds, anilines and C,N-cyclic azomethine imines via trapping of transient ammonium ylides was developed. This reaction provided a simple and convenient approach for the synthesis of pharmaceutically intriguing tetrahydroisoquinoline derivatives in moderate to good yields (36–85%) with good diastereoselectivities (up to 95 : 5 dr) under mild reaction conditions