Phosphine–Borane Ligands Induce Chemoselective Activation and Catalytic Coupling of Acyl Chlorides at Palladium

Abstract

Acyl chlorides are highly reactive and widely used substrates in catalytic cross-coupling reactions, but so far, site selectivity over other functional groups has remained an issue. In this work, Pd complexes deriving from the phosphine−boranes [i-Pr 2 P(o-C 6 H 4 )] 2 BFXyl and i-Pr 2 P(o-C 6 H 4 )-BFXyl 2 (Fxyl = 3,5-(F 3 C) 2 C 6 H 3 ) were found to preferentially activate acyl chlorides over C−I, C−Br, C−Cl, C−OTf, and C−OTs bonds. The system is amenable to catalysis (Stille and Negishi couplings), providing a simple and efficient means to forge C(O)−C bonds in a site-selective manner and to readily access functionalized ketones. To gain insight into the role and influence of the ambiphilic ligands, key Pd complexes have been authenticated and the reaction profiles have been analyzed by density functional theory (DFT) calculations.

How Cationic Metalloligands Affect the Coordination of Lewis Basic Ligands in RhIComplexes

“…The competence in hydroformylation is evaluated. For this goal we chose the more electron-rich DCPTPA ligand framework ( d i c yclohexyl p hosphino t ris p yridyl a mine) over the previous DPPTPA ( d i p henyl p hosphino t ris p yridyl a mine) ligand used in DPPTPA-M , as previous studies revealed that stabilization of low oxidation states by acceptor ligand coordination inhibits oxidative addition …”

C−H Silylation of 2‐Arylpyridine Derivatives by Using Iridium Catalyst and Phosphine‐Borane Ligand

“…A variety of ambiphilic ligands for bifunctional catalysts have been reported so far [8] . Above all, palladium/phosphine‐borane catalyst system have been used for many types of catalytic organic reactions, such as hydroboration, [9] cyanoboration, [10] Suzuki‐Miyaura coupling, [11] hydrodechlorination, [12] and cross‐coupling of acyl chlorides [13] . In addition, our group found that a palladium/phosphine‐borane complex is a good catalyst for the allylation and benzylation reactions using allylic and benzylic alcohols [14] .…”

“…[8] Above all, palladium/phosphine-borane catalyst system have been used for many types of catalytic organic reactions, such as hydroboration, [9] cyanoboration, [10] Suzuki-Miyaura coupling, [11] hydrodechlorination, [12] and cross-coupling of acyl chlorides. [13] In addition, our group found that a palladium/phosphine-borane complex is a good catalyst for the allylation and benzylation reactions using allylic and benzylic alcohols. [14] In these reactions, we think that a Lewis acidic boryl group activates the hydroxy group of allylic and benzylic alcohols.…”

Novel Naphthalimide‐Based Self‐Assembly Systems with Different Terminal Groups for Sensitive Detection of Thionyl Chloride and Oxalyl Chloride in Two Modes

“…[1][2][3][4] For example, acyl chlorides can react with alcohols, amine and arenes for preparation of ester, amide and aldehydes derivatives. [5][6] But the boiling points of acyl chlorides are very low, such as (COCl) 2 with 63 °C, acetyl chloride with 51 °C and phosgene with 8.2 °C.…”

“…Acyl chlorides are frequently used in industrial manufacture and laboratory for the synthesis of various compounds including medical intermediate, materials, pesticide, and so on [1–4] . For example, acyl chlorides can react with alcohols, amine and arenes for preparation of ester, amide and aldehydes derivatives [5–6] . But the boiling points of acyl chlorides are very low, such as (COCl) 2 with 63 °C, acetyl chloride with 51 °C and phosgene with 8.2 °C.…”