312329-83-2Relevant academic research and scientific papers
Efficient and Flexible Synthesis of Highly Functionalised 4-Aminooxazoles by a Gold-Catalysed Intermolecular Formal [3+2] Dipolar Cycloaddition
Gillie, Andrew D.,Jannapu Reddy, Raju,Davies, Paul W.
, p. 226 - 239 (2016/02/14)
Oxazoles are important motifs within bioactive and functional materials. Complex, fully substituted and functionalised 4-aminooxazoles are accessed by an efficient intermolecular reaction between an ynamide and an N-acylpyridinium N-aminide in the presence of a gold catalyst. The formal [3+2] dipolar cycloaddition employs a nucleophilic nitrenoid approach to access the 1,3-N,O-dipole character in a controllable fashion. The selectivity for a cycloaddition pathway provides a stark contrast against the indiscriminate reactivity of electrophilic acyl nitrenes. Protocols for the formation of acyl-functionalised aminides are reported from accessible precursors including carboxylic esters and acids. The function of these aminides in the oxazole-forming reaction has been explored and it is shown that substantial elaboration is accommodated despite proximity to the reactive centre. As a result functional oxazole-based motifs, such as chiral oxazoles with biologically pertinent substitution patterns, are readily accessible. The use of ynamide types that are unexplored or little used in gold catalysis has been evaluated. Unusual all-heteroatom substitution patterns around the oxazole are shown to be accessible using thio-ynamides. The study shows that a close stoichiometry of reactants is suitable alongside relatively low loadings of the bench-stable precatalysts in practically straightforward multi-mmol scale reactions. The efficiency and flexibility of this regioselective intermolecular preparation is demonstrated in the ready synthesis of oxazoles with substantial structural and functional group variation.
Copper(I)-catalyzed nucleophilic addition of ynamides to acyl chlorides and activated N-heterocycles
Zhang, Peng,Cook, Andrea M.,Liu, Yang,Wolf, Christian
, p. 4167 - 4173 (2014/05/20)
The addition of ynamides to acyl chlorides and N-heterocycles activated in situ with ethyl chloroformate has been accomplished at room temperature using copper iodide as catalyst. This economical and practical carbon-carbon bond formation provides convenient access to a variety of 3-aminoynones from aliphatic and aromatic acyl chlorides in up to 99% yield. The addition to pyridines and quinolines occurs under almost identical conditions and proceeds with good to high regioselectivity, producing the corresponding 1,2-dihydro-N-heterocycles in up to 95% yield.
Palladium-mediated [2+1] cycloaddition of norbornene derivatives with ynamides
Clavier, Herve,Lepronier, Aymeric,Bengobesse-Mintsa, Nathalie,Gatineau, David,Pellissier, Helene,Giordano, Laurent,Tenaglia, Alphonse,Buono, Gerard
, p. 403 - 408 (2013/05/22)
An efficient palladium-catalyzed [2+1] cycloaddition between ynamides and norbornenes or norbornadienes is reported. Both phosphapalladacycles and palladium/secondary phosphine oxide catalytic systems were found to be competent for the transformation allowing the preparation of aminomethylenecyclopropanes. The reaction showed general applicability to various functionalized bicyclo[2.2.1]hept-2-enes and ynamides. A chiral phosphapalladacycle was tested to carry out this transformation in an enantioselective fashion.
Synthesis of ynamides from formamides
Brückner, David
, p. 3809 - 3814 (2007/10/03)
N-Formyl-tosylamides can be efficiently converted to N-ethynyl-tosylamides in two steps via the corresponding dichlorovinylamides.
Synthesis of ynamides and ynol ethers via formamides and formates
Bruckner
, p. 1402 - 1404 (2007/10/03)
The efficient conversion of N-formyl-tosylamides to N-ethynyl-tosylamides via the corresponding dichlorovinylamides is described. Furthermore syntheses of N-formyl-tosylamides are reported.
