Since the isomerization of C–C multiple bonds is a powerful strategy in organic synthesis, in this study we have investigated the isomerization upon metalation of 1-phenylpropyne with alkyllithium bas...

The nickel-catalyzed Kumada–Tamao–Corriu cross-coupling reaction is widely used to form C–C bonds and receives continued interest due to the unique ability of nickel to activate challenging organic electrophiles containing C–F and C–O bonds. Recent studies on the nickel-catalyzed cross-coupling of Ar–F and Ar–OMe electrophiles with organolithium nucleophiles have unveiled the key involvement of highly reactive anionic nickelates, in which Li and Ni cooperatively promote the activation of these substrates. However, the possible formation of related heterobimetallic intermediates when employing organomagnesium nucleophiles as cross-coupling partners still remains widely underexplored. Filling this gap in the knowledge, we use air-stable Ni-tris(olefin), Ni(4-Me-stb)3 (where stb = stilbene), as a Ni(0) precursor to systematically investigate its reactivity toward several organomagnesium and organolithium reagents, which has allowed for the structural and spectroscopic characterization of a new family of nickelate complexes. Their possible implications and the influence of their constitution and speciation on the outcome of Kumada–Tamao–Corriu cross-couplings are also investigated through a series of stoichiometric and catalytic reactions, which have uncovered a dramatic solvent effect, hinting at the formation of contacted ion pair species as key to maximizing Mg (or Li)/Ni(0) cooperativity.

Despite the abundance and non-toxic nature of sodium, organosodium reagents have rarely been used in organic synthesis. Now iron-catalysed homocoupling and C(sp2)–C(sp3) cross-coupling reactions of ar...

Despite the abundance and non-toxic nature of sodium, organosodium reagents have rarely been used in organic synthesis. Now iron-catalysed homocoupling and C(sp2)–C(sp3) cross-coupling reactions of ar...

Researchers from the University of Bern and the RIKEN research institute in Japan have made a significant advance in sustainable chemistry. They have succeeded in producing organic molecules through a...

Cobalt(II) bis(amides)are widely applied in catalysis and material science. Typically, they are prepared via salt metathesis, by reacting a lithium amide with a CoX2 (X = Cl, Br) salt, requiring, in many cases, the use of low temperatures and other solvents. This work introduces an alternative approach, assessing the reactivity of classical Co(II) amide [Co(HMDS)2] (1) [HMDS = N(SiMe3)2] and heterobimetallic [NaCo(HMDS)3] (6) as precursors for trans(amination) reactions with DPA(H) (2,2′-dipyridylamine), N-methylaniline, and piperidine. When reacted with the most acidic amine DPA(H), both showed polybasic behavior with excellent stoichiometric control according to the equivalents of DPA(H) employed. Reactions with and piperidine led to an incomplete exchange of the HMDS groups present in 1, even when an excess of the relevant amine is employed. Contrastingly, when assessing the reactivity of sodium cobaltate 6 with these amines, kinetic activation of two (or three) of its HMDS-arms was observed, forming new heterobimetallic species which in all cases proved unstable, undergoing dissociation into their monometallic components or a ligand redistribution process. The catalytic potential of the novel Co(II) complexes was investigated for the hydrosilylation of acetophenone, finding that faster reaction rates and higher chemoselectivities were achieved when using the heterobimetallic Na/Co systems.

PhD Project - Programming Copper–Zinc Heteromultimetallic Complexes for CO2 Reduction at University of Bath, listed on FindAPhD.com