Stille Coupling Made Easier—The Synergic Effect of Copper(I) Salts and the Fluoride Ion

Abstract

CsF and CuI do the trick: Stille coupling reactions of aryl/vinyl iodides, triflates, and bromides with aryl/vinyl stannanes are greatly enhanced by the inclusion of CsF and CuI in the reaction mixture (see scheme; Conditions A: [Pd(PPh3)4]/CsF/CuI/DMF/45 °C; Conditions B: PdCl2/PtBu3/CsF/CuI/DMF/45 °C).

Synthesis and Anti-HIV Activity of New Metabolically Stable Alkenyldiarylmethane Non-Nucleoside Reverse Transcriptase Inhibitors Incorporating N-Methoxy Imidoyl Halide and 1,2,4-Oxadiazole Systems

“…The key functional groups, Nmethoxy imidoyl chloride and bromide, were introduced after the construction of the ADAM framework in order to avoid the risk of Pd-catalyzed reactions with the imidoyl halides. In the next step, the Stille coupling of 20 with 21 13 was attempted using the reaction conditions previously described by Mee et al 23 The significant feature of their conditions is that addition of a catalytic amount of cuprous iodide accelerates the reaction rate in a highly polar solvent such, as DMF. However, in the case of the reaction of 20 with 21 13 , no reaction was observed, probably due to the chelation of the N-methoxyamide group of 20 and the neighboring methoxy group to Pd II -complexes.…”

Copper(II) Fluoride a New Efficient Promoter of Chan-Lam-Evans Coupling

“…The cleavage of the boron-carbon bond might be assisted by the acetate ligand of the complex, by forming a neutral leaving species. Because fluoride ion proved to be efficient in other coupling reactions [8,9,10] we performed the transmetallation step with copper(II) fluoride (Fig. 1b).…”

“…In most cases the promoter is used in equimolar quantity and also oxygen from air is necessary. Fluoride ions are known to assist the Suzuki [8], Stille [9] and Hiyama [10] cross-coupling reactions, by cleaving the carbonheteroatom bond in the transmetallation step of the reactions. In this article we report the application of copper(II) fluoride reagent in the Chan-Lam-Evans coupling.…”

Design and synthesis of organic sensitizers with enhanced anchoring stability in dye-sensitized solar cells

“…Optimal conditions to react stannane 3 with regioisomeric bromopyridines 5a,b,c were found using Pd(PPh 3 ) 4 as catalyst, oxygenfree DMF as solvent, CsF and CuI as additives [32], giving rise to pyiridine-containing intermediates 6a,b,c. It is worth mentioning that the same compounds could also be obtained using a Suzuki-Miyaura cross-coupling between the pinacolboronic ester corresponding to stannane 3 and the appropriate heterocycle.…”