A Robust and Broadly Applicable Cobalt‐Catalyzed Cross‐Coupling of Functionalized Bench‐Stable Organozinc Pivalates with Unsaturated Halides

Abstract

We report ar obust and broadly applicable CoCl 2catalyzedc ross-coupling between functionalizeda ryl and heteroaryl zinc pivalates and various electron-poor aryl and heteroaryl halides (X = Cl, Br,I). Couplings with (E)-or (Z)bromo-or iodo-alkenes proceed with retention of configuration. Also,a lkynyl bromides react with arylzinc pivalates providing arylated alkynes.

Preparation and characterization of Cu supported on 2‐(1H‐benzo[d]imidazol‐2‐yl)aniline‐functionalized Fe3O4 nanoparticles as a novel magnetic catalyst for Ullmann and Suzuki cross‐coupling reactions

“…One-pot reactions of diaryl derivatives using Cu-BIA-Si-Fe 99.4-101.4 [44] TON: turnover number, yield of product/mol of Cu).…”

Recent Advances in Cobalt-Catalyzed Csp2 and Csp3 Cross-Couplings

“…the cross-coupling between 3-N,N-dimethylaminophenylmagnesium bromide (6) and methyl 2-chloronicotinate (7) in the presence of 3 mol% CoCl 2 at 25 °C produces the desired cross-coupling product 8 within 10 minutes, albeit in only 10% yield. Extension of the reaction time did not increase the product formation.…”

“…Thus, all three iodobenzonitriles (ortho, meta, and para) 26a-c react with p-anisylzinc pivalate (27) to give the expected cross-coupling products 28a-c in 71-75% yield using only 5 mol% CoCl 2 in the absence of any additional ligand (40 °C, 16 h; Scheme 12). 7 Various heterocyclic bromides such as 29-32 undergo smooth cross-couplings under mild conditions. In the case of chloropyrazine 31, the reaction was performed on a gram scale without a drop in the yield (Scheme 13).…”

Cobalt-Catalyzed Cross-Couplings of Bench-Stable Alkynylzinc Pivalates with (Hetero)Aryl and Alkenyl Halides

“…Recently, there has been much progress in Co-catalyzed coupling methods . Despite the recent advances in Co-catalyzed coupling reactions between C­(sp 2 ) and C­(sp 3 ) centers using magnesium or zinc reagents, no Co-catalyzed Negishi-type coupling reactions using alkynylzinc reagents have been described. However, the air and moisture sensitivity of alkynylzinc reagents (RZnX, X = Hal) often limits their synthetic applications.…”