Ruthenium- and gold-catalysed sequential reactions: a straightforward synthesis of substituted oxazoles from propargylic alcohols and amides

Milton, Marilyn Daisy; Inada, Youichi; Nishibayashi, Yoshiaki; Uemura, Sakae

doi:10.1039/b411180j

Cited by 153 publications

(54 citation statements)

References 19 publications

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“…In a manuscript which appeared at the same time, Uemura et al reported a combination of a ruthenium-catalyzed formation of the N-propargyl carboxamides 6 from carboxamides 5 and propargyl alcohols 4 and the subsequent gold-catalyzed formation of oxazoles (Scheme 5) [12]. For the gold-catalyzed part, quite different from The synthetic scope of the gold(III)-catalyzed oxazole synthesis is quite broad (Scheme 7), even very bulky substituents, olefinic and heterocyclic substitutents are tolerated.…”

Section: Gold(iii) Precatalysts Deliver Aromatic Oxazolesmentioning

confidence: 95%

Gold-catalyzed synthesis of N,O-heterocycles

Hashmi

2010

Pure and Applied Chemistry

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The selective synthesis of oxazoles, alkylidene oxazoles, and 1,3-oxazines from N-propargyl carboxamides by choosing gold(III) or gold(I) catalysts and selecting terminal or internal alkynes as substrates is discussed. The mechanistic studies based on labeling experiments and intensive in situ NMR studies indicate an anti-oxyauration step and a protodeauration with retention of the sterical arrangement at the double bond. The synthetic scope for gold(I) catalysts is very broad, allowing selective conversions to products with properties of chelate ligands, reactions of bromoarenes and the formation of acceptor-substituted oxazoles. With N-heterocyclic carbene (NHC) ligands in the presence of a base, even the vinylgold intermediates of the reactions leading to 1,3-oxazines could be isolated, a reaction with a great potential for future mechanistic studies and future applications of gold catalysis.

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Section: Gold(iii) Precatalysts Deliver Aromatic Oxazolesmentioning

confidence: 95%

Gold-catalyzed synthesis of N,O-heterocycles

Hashmi

2010

Pure and Applied Chemistry

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“…The reaction proceeds via formation of propargyl amide 5-63 , followed by the Au(III)-catalysed cycloisomerization (see also Scheme 333) into oxazole 5-62 . 505 …”

Section: Synthesis Of 5-membered Heterocycles With Two or More Hetmentioning

confidence: 99%

Transition Metal-Mediated Synthesis of Monocyclic Aromatic Heterocycles

et al. 2013

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“…Electron-rich arenes can displace a primary sulfonate ester on an alkyl chain leading to a linear product (eq 32). 50 Ar-H OTf + Ar 5 mol % AuCl 3 15 mol % AgOTf n DCE, 120 °C n isolated yield: 51-85% (32) However, when a nonactivated arene was used (such as benzene), branched products are formed almost exclusively. On the other hand, the reaction can also proceed intramolecularly leading to cyclic structures.…”

Section: Tandem Reactions Involving Friedel-crafts Type Additionmentioning

confidence: 99%