Rh^I‐Catalyzed P^III‐Directed C−H Bond Alkylation: Design of Multifunctional Phosphines for Carboxylation of Aryl Bromides with Carbon Dioxide

Abstract

We report the C−H alkylation of biarylphosphines at the ortho′ position(s) with alkenes by using rhodium(I) catalysis, which provides straightforward access to a large library of multifunctionalized phosphines. Some of these modified ligands outperformed commercially available phosphines in the Pd‐catalyzed carboxylation of aryl bromides with carbon dioxide in the presence of a photoredox catalyst.

Synthesis of Carboxylic Acids by Palladium‐Catalyzed Hydroxycarbonylation

“…After demonstrating the viability of our system for industrial aliphatic olefins, we were interested in the hydroxycarbonylation of aromatic and functionalized alkenes, which are of interest for fine chemicals, specialties, and organic synthesis (Table ) . As an example, styrene ( 1 y ) was completely converted with 83 % regioselectivity towards 3‐phenyl propionic acid ( 2 y ; entry 1).…”

Recent Advancements in Transition‐Metal‐Catalyzed One‐Pot Twofold Unsymmetrical Difunctionalization of Arenes

“…Very recently, Soulé and co‐workers disclosed a Rh I ‐catalyzed P III ‐directed C−H bond alkylations en route to a library of phosphines with pendant alkyl groups (Scheme ) . Initially, the phosphine was reacted with first olefin in presence of potassium acetate and rhodium catalyst in toluene at 160 °C for 24 h. Thereafter, the second olefin was introduced, which ultimately gave access to unsymmetrically functionalized phosphines in good yields.…”

RhI‐Catalyzed PIII‐Directed C−H Bond Alkylation: Design of Multifunctional Phosphines for Carboxylation of Aryl Bromides with Carbon Dioxide

“…[20] Unprecedented phosphine 4h,w hich contains multiple hemilabile groups,w as prepared in 64 % yield through iterative two-fold CÀHa lkylations using first acrylamide followed by methylacrylate.T he multifunctional phosphine 4i was obtained through the alkylation of 1a with 4-methoxystyrene and methylacrylate.T op roduce al ongchain bifunctional phosphine for ac atalyst that operates in water, the multifunctional phosphine 4j was prepared using eicosyl acrylate and acrylamide as the two alkene sources. Thecoupling of cyclohexyl or phenyl JohnPhos with two different acrylate esters afforded the dissymmetrical diester-phosphines 4fand 4g in good yields.The structure of 4g was confirmed by X-ray diffraction analysis.…”