Copper salt-catalyzed homo-coupling reaction of potassium alkynyltrifluoroborates: a simple and efficient synthesis of symmetrical 1,3-diynes

A Scalable Synthesis of the Difluoromethyl-allo-threonyl Hydroxamate-Based LpxC Inhibitor LPC-058

The difluoromethyl-allo-threonyl hydroxamate-based compound LPC-058 is a potent inhibitor of UDP-3-O-(R-3-hydroxymyristoyl)-N-acetylglucosamine deacetylase (LpxC) in Gram-negative bacteria. A scalable synthesis of this compound is described. The key step in the synthetic sequence is a transition metal/base-catalyzed aldol reaction of methyl isocyanoacetate and difluoroacetone, giving rise to 4-(methoxycarbonyl)-5,5-disubstituted 2-oxazoline. A simple NMR-based determination of enantiomeric purity is also described.

Recent advances and applications of Glaser coupling employing greener protocols

Recent developments in Glaser coupling catalysed by copper(i) is discussed in the review with emphasis on its application.

A facile copper(I)-catalyzed homocoupling of terminal alkynes to 1,3-diynes with diaziridinone under mild conditions

A novel and efficient Cu(I)-catalyzed oxidative homocoupling of terminal alkynes with diaziridinone as an oxidant is described. Various terminal alkynes can be transformed into the corresponding 1,3-diynes in good yields. The reaction process is base-free, operationally simple, and amenable to the gram scale.

Copper-catalyzed alkynylation of amides with potassium alkynyltrifluoroborates: a room-temperature, base-free synthesis of ynamides

An efficient copper-mediated method for the coupling of potassium alkynyltrifluoroborates with nitrogen nucleophiles is reported. This reaction provides the first base-free and room-temperature synthesis of ynamides and allows for an easy preparation of these useful building blocks.

(1)H, (13)C, (19)F and (11)B NMR spectral reference data of some potassium organotrifluoroborates

Complete (1)H, (13)C, (19)F and (11)B NMR spectral data for 28 potassium organotrifluoroborates are described. The resonance for the carbon bearing the boron atom is described for most of the studied compounds. A modified (11)B NMR pulse sequence was used and better resolution was observed allowing the observation of (11)B-(19)F coupling constants for some of the studied compounds.