123387-49-5Relevant articles and documents
Cobalt-Catalyzed C(sp2)-C(sp3) Suzuki-Miyaura Cross-Coupling Enabled by Well-Defined Precatalysts with L,X-Type Ligands
Chirik, Paul J.,Gygi, David,Kim, Junho,Ludwig, Jacob R.,Mills, L. Reginald,Simmons, Eric M.,Wisniewski, Steven R.
, p. 1905 - 1918 (2022/02/07)
Cobalt(II) halides in combination with phenoxyimine (FI) ligands generated efficient precatalysts in situ for the C(sp2)-C(sp3) Suzuki-Miyaura cross-coupling between alkyl bromides and neopentylglycol (hetero)arylboronic esters. The protocol enabled efficient C-C bond formation with a host of nucleophiles and electrophiles (36 examples, 34-95%) with precatalyst loadings of 5 mol %. Studies with alkyl halide electrophiles that function as radical clocks support the intermediacy of alkyl radicals during the course of the catalytic reaction. The improved performance of the FI-cobalt catalyst was correlated with decreased lifetimes of cage-escaped radicals as compared to those of diamine-type ligands. Studies of the phenoxyimine-cobalt coordination chemistry validate the L,X interaction leading to the discovery of an optimal, well-defined, air-stable mono-FI-cobalt(II) precatalyst structure.
Sustainable Route Toward N-Boc Amines: AuCl3/CuI-Catalyzed N-tert-butyloxycarbonylation of Amines at Room Temperature
Cao, Yanwei,He, Lin,Huang, Yang
, (2021/12/22)
N-tert-butoxycarbonyl (N-Boc) amines are useful intermediates in synthetic/medicinal chemistry. Traditionally, they are prepared via an indirect phosgene route with poor atom economy. Herein, a step- and atom-economic synthesis of N-Boc amines from amines, t-butanol, and CO was reported at room temperature. Notably, this N-tert-butyloxycarbonylation procedure utilized ready-made substrates, commercially available AuCl3/CuI as catalysts, and O2 from air as the sole oxidant. This catalytic system provided unique selectivity for N-Boc amines in good yields. More significantly, gram-scale preparation of medicinally important N-Boc amine intermediates was successfully implement, which demonstrated a potential application prospect in industrial syntheses. Furthermore, this approach also showed good compatibility with tertiary and other useful alcohols. Investigations of the mechanisms revealed that gold catalyzed the reaction and copper acted as electron transfer mediator in the catalytic cycle.
Ni-Catalyzed Electrochemical Decarboxylative C-C Couplings in Batch and Continuous Flow
Li, Hui,Breen, Christopher P.,Seo, Hyowon,Jamison, Timothy F.,Fang, Yuan-Qing,Bio, Matthew M.
supporting information, p. 1338 - 1341 (2018/03/09)
An electrochemically driven, nickel-catalyzed reductive coupling of N-hydroxyphthalimide esters with aryl halides is reported. The reaction proceeds under mild conditions in a divided electrochemical cell and employs a tertiary amine as the reductant. This decarboxylative C(sp3)-C(sp2) bond-forming transformation exhibits excellent substrate generality and functional group compatibility. An operationally simple continuous-flow version of this transformation using a commercial electrochemical flow reactor represents a robust and scalable synthesis of value added coupling process.