Optimization study of Sonogashira cross-coupling reaction on high-loading macrobeads using a silyl linker

A dramatic enhancing effect of InBr3 towards the oxidative Sonogashira cross-coupling reaction of 2-ethynylanilines

The addition of InBr3 to the oxidative Sonogashira cross-coupling reaction of 2-ethynylaniline with (E)-trimethyl(3,3,3-trifluoroprop-1-enyl)silane led to a dramatic increase in the reactivity to afford the corresponding 1,3-enynes bearing a trifluoromethyl group on their terminal sp(2) carbon. The subsequent cyclization of these 1,3-enynes under palladium catalysis provides access to the corresponding indoles bearing a 3,3,3-trifluoroprop-1-enyl group at their 2-position.

Synthesis of Conformationally Constrained Cyclic Peptides Using an Intramolecular Sonogashira Coupling

[Reaction: see text]. Small peptides having a 3-bromobenzyl group at the C-termini and n-alkynoyl group at the N-termini undergo a smooth copper-free intramolecular Sonogashira coupling reaction to afford the corresponding cyclic peptides in moderate yields. Scope and limitations of this macrocyclization is demonstrated with di-, tri-, and tetrapeptides.

Copper-Free Sonogashira Coupling Reaction with PdCl2 in Water under Aerobic Conditions

A mild protocol for the copper-free Sonogashira coupling of aryl iodides with terminal acetylenes in water under aerobic conditions has been developed. The use of 1 mol % PdCl(2) in the presence of pyrrolidine allows the coupling reaction to proceed at room temperature or 50 degrees C with good to excellent yields.

Synthesis of Conformationally Restricted 2,3-Diarylbenzo[b]furan by the Pd-Catalyzed Annulation of o-Alkynylphenols: Exploring a Combinatorial Approach

The palladium/bpy-catalyzed annulation of o-alkynylphenol with various aryl halides to generate diversified 2,3-diarylbenzo[b]furan is herein described. This method provides an efficient synthetic pathway for the combinatorial synthesis of conformationally restricted 2,3-diarylbenzo[b]furan for drug discovery.

Total Synthesis of Wedelolactone

The total synthesis of wedelolactone, a naturally occurring direct inhibitor of IKK complex that can suppress LPS-induced caspase-11 expression, using a convergent synthetic approach, is described. The key steps involved in this synthesis include the palladium-catalyzed Sonogashira reaction and the palladium-catalyzed carbonylative annulation reaction. This approach allows access to diversified analogues of wedelolactone.

Rapid microwave promoted Sonogashira coupling reactions on solid phase

A microwave-enhanced, rapid, and efficient solid-phase version of the Sonogashira reaction is presented. It has been applied to the coupling of aryl iodides and bromides with various acetylene derivatives giving excellent yields in 15-25 min. The scopes of homogeneous, solventless, and solid-phase conditions for Sonogashira coupling of aryl halides are compared.

Palladium-catalyzed cross-coupling reactions of 4-tosyl-2(5H)-furanone with boronic acids: a facile and efficient route to generate 4-substituted 2(5H)-furanones

An efficient and facile synthesis of 4-substituted 2(5H)-furanones using palladium catalyzed cross-coupling reactions between 4-tosyl-2(5H)-furanone and boronic acids is reported herein.