Development of Efficient and Reusable Diarylphosphinopolystyrene‐Supported Palladium Catalysts for CC Bond Forming Cross‐Coupling Reactions

Abstract

3c is the most active catalyst for Heck reactions. The couplings are performed under non-anhydrous reaction conditions and require only low amounts of supported palladium (0.5 mequivs. for Suzuki-Miyaura, 1.0 mequiv. for Sonogashira and 0.5 mequivs. for Heck reactions could be sufficient). Catalysts 3a-j are recovered by filtration and can be reused more than four times with no loss of efficiency.

Practical Synthesis of SimplePhos Ligands: Further Development of Alkyl‐Substituted Phosphanamines

“…Reports in the literature describe the addition of cyclohexane to the crude solution and careful removal of THF by co‐evaporation with cyclohexane 13. In contrast, Manners15 and Le Drian16 and their co‐workers reported the use of aryllithium reagents instead of Grignard reagents, which were prepared by bromine/lithium exchange in diethyl ether or hexanes. Note that Manners only reported one exchange with n BuLi for an electron‐poor aryl bromide whereas Le Drian used 2 equiv.…”

Polymers for Green C–C Couplings

“…[52] The same systems (1, R = Ar) react with Pd(PPh 3 ) 4 , whereupon the four PPh 3 ligands are eliminated; the system has been used in Suzuki, Sonogashira, and Heck couplings, and it is recyclable at least four times. [53] As their homogeneous analogues, the use of polystyrenesupported phosphanes with bulky substituents lead to catalytic systems that are active in the Suzuki coupling of the reluctant aryl chlorides; an example is ligand 3 (R = Cy, Figure 1). [54] Buchwald et al prepared supported phosphane 4 (R = Cy, Figure 1), and upon reaction with Pd(OAc) 2 or Pd 2 dba 3 , obtained a colored polymer that is active in the coupling of ArCl (as well as ArBr) and aryl boronic acids.…”

Recyclable nickel catalysed Suzuki–Miyaura reaction in the presence of polyethyleneimine under phosphine-free conditions in ethylene glycol#

“…In addition, contamination of the products by the metal residues, even after purification step, is a sharp problem for large-scale operation in pharmaceutical industries. [39][40][41][42][43][44][45][46][47][48][49][50][51] Polyethyleneimine has been widely used for preparation of polymer supported phase-transfer catalysts. Its physicochemical incompatibility with solvents and substrates most often leads to high efficiency and reactivity.…”