Palladium(I) Dimer Enabled Extremely Rapid and Chemoselective Alkylation of Aryl Bromides over Triflates and Chlorides in Air

Abstract

Disclosed herein is the first general chemoand site-selective alkylation of CÀBr bonds in the presence of COTf,C ÀCl and other potentially reactive functional groups,u sing the air-, moisture-, and thermally stable dinuclear Pd I catalyst, [Pd(m-I)PtBu 3 ] 2 .T he bromo-selectivity is independent of the substrate and the relative positioning of the competing reaction sites,and as such fully predictable. Primary and secondary alkylc hains were introduced with extremely high speed (< 5min reaction time) at room temperature and under open-flask reaction conditions.

Isolation and Catalytic Reactivity of Mononuclear Palladium(I) Complexes

“…In order to analyze the catalytic competency of the isolated Pd I complexes, the Kumada crosscoupling reaction between bromobenzene and a secondary alkyl nucleophile, cyclohexylMgCl, was employed, since such Csp 3 -Csp 2 cross-coupling reactions catalyzed by Pd are rare. 16,[35][36][37][38] The Pd-2 complex, either generated in situ or used as isolated, shows very good catalytic activity (86% by GC-FID) under mild conditions (Table 2, entries 1 and 2, respectively), and a gram-scale reaction reveals a similar yield (Fig. S38).…”

Modular and Selective Arylation of Aryl Germanes (C−GeEt3) over C−Bpin, C−SiR3 and Halogens Enabled by Light‐Activated Gold Catalysis

“…To illustrate this further (Figure 3), we applied our newly developed protocol to poly-functionalized substrates (54, 56, 58, and 60) and performed a fully selective arylation of the germanium group in the presence of CÀBr, CÀBpin, and/or CÀSiMe 3 . The resulting biaryl scaffolds were further diversified by rapid and air-tolerant arylation or alkylation of CÀBr enabled by Pd I -iodo dimer chemistry [3,25] as well as Chan-Lam or Suzuki couplings of C À BPin and iodination and acetoxylation of C À SiMe 3 .…”

Tandem Photoredox Catalysis: Enabling Carbonylative Amidation of Aryl and Alkylhalides

“…Modern synthetic methods typically employ stoichiometric coupling reagents to mediate the condensation of a carboxylic acid and amine ( Figure 1a). 4 These protocols liberate equivalents of toxic by-products and are generally incompatible with sterically congested amides. 5 Given the prevalence of the amide functionality in pharmaceutical and agrochemicals, scaled processes are impeded by the expense associated with high molecular weight coupling reagents and the environmental impact of super-stoichiometric waste streams.…”