Palladium-catalyzed cross-coupling reaction of alkenyl bromides with potassium alkyltrifluoroborates

Abstract

The Suzuki-Miyaura-type cross-coupling reaction of potassium alkyltrifluoroborates with various alkenyl bromides in the presence of 10 mol % of PdCl(2)(dppf)·CH(2)Cl(2) and 3.0 equiv of Cs(2)CO(3) in aqueous toluene at 80 °C provided the desired compounds in 49-95% yields. A variety of functional groups in the potassium alkyltrifluoroborates were tolerated under the basic conditions.

Organotrifluoroborates: Protected Boronic Acids That Expand the Versatility of the Suzuki Coupling Reaction

“…35 The reaction conditions are tolerant of a variety of functional groups, and a diverse array of substitution patterns can be accessed in a completely stereospecific manner.…”

Enantioselective Synthesis of Lepadins A–D from a Phenylglycinol‐Derived Hydroquinolone Lactam

“…The required d-keto ester 3,b earing at rimethylsilylethyl (TMSE)-protected hydroxymethyls ubstituent, was prepared in two steps from diketo ester 1,b yP d-catalyzedc ross-coupling of either the corresponding vinyl triflate or,m ore conveniently,b romo enone withp otassium alkoxymethyltrifluoroborate 2 (Scheme 3). [15] Ac yclocondensation reactiono fd-keto ester 3 with (R)-phenylglycinol, followed by catalytic hydrogenationo ft he resulting mixture of endocyclic and exocyclic unsaturated lactams led to saturated tricyclic lactam 4 in 67 %overall yield. [16] The reductive opening of the oxazolidine ring was accomplished with complete retention of configuration by alane reduction, which also caused the reductionofthe lactam carbonyl.…”

ChemInform Abstract: Potassium Trifluoroborate Salts as Convenient, Stable Reagents for Difficult Alkyl Transfers

“…The cross-coupling of potassium primary alkyltrifluoroborates has also been demonstrated with alkenyl bromides [xxv]. Using 10 mol % of PdCl 2 (dppf)·CH 2 Cl 2 and Cs 2 CO 3 (3 equiv) and a toluene/H 2 O solvent system, various alkenyl bromides underwent conversion to generate the cross-coupled products in good yields.…”