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
A simple and practical synthesis of ynones directly from readily available aldehydes was developed for the first time under mild reaction conditions via a Rh(III)- or Ir(III)-catalyzed formyl C-H bondactivation.
A transition-metal-free synthetic method of various ynones via decarboxylative alkynylation of α-keto acids is described. The reaction is carried out undermildconditions and exhibits remarkable tolerance of functional groups. The mechanism of a radical process is proposed in the reaction.
Ethynyl Benziodoxolones for the Direct Alkynylation of Heterocycles: Structural Requirement, Improved Procedure for Pyrroles, and Insights into the Mechanism
作者:Jonathan P. Brand、Clara Chevalley、Rosario Scopelliti、Jérôme Waser
DOI:10.1002/chem.201200200
日期:2012.4.27
accelerating effect of a methyl substituent in both the 3‐ and 6‐position of triisopropylsilylethynyl‐1,2‐benziodoxol‐3(1H)‐one (TIPS‐EBX) on the reaction rate was observed. Competitive experiments between substrates of different nucleophilicity, deuterium labeling experiments, as well as the regioselectivity observed are all in agreement with electrophilic aromatic substitution. Gold(III) 2‐pyridinecarboxylate
Synthesis, Characterization of Spirocyclic λ
<sup>3</sup>
‐Iodanes and Their Application to Prepare 4,1‐Benzoxazepine‐2,5‐diones and 1,3‐Diynes
作者:Xu Sun、Xiao‐Qiang Guo、Lian‐Mei Chen、Tai‐Ran Kang
DOI:10.1002/chem.202005124
日期:2021.3
cycloaddition of aza‐oxyallylic cations with ethynylbenziodoxolones for synthesis of new λ3‐iodanes containing spirocyclic 4‐oxazolidinone has been developed. This cyclic λ3‐iodanes display stability in air and excellent solubility in organic solvent. Using them as substrate, both the 4,1‐benzoxazepine‐2,5‐diones and symmetrical 1,3‐diynes derivatives were afforded in high yield under copper(I)‐catalyzed