Ruben Martin

Metal-Catalyzed Reductive Coupling Reactions of Organic Halides with Carbonyl-Type Compounds

Metal-catalyzed reductive coupling reactions of aryl halides and (pseudo)halides with carbonyl-type compounds have undergone an impressive development within the last years. These methodologies have shown to be a powerful alternate strategy, practicality aside, to the use of stoichiometric, well-defined, and, in some cases, air-sensitive organometallic species. In this Minireview, the recent findings in this field are summarized, with particular emphasis on the mechanistic interpretation of the results and future aspects of this area of expertise.

Nickel-Catalyzed Carboxylation of Benzylic C-N Bonds with CO2.

A user-friendly Ni-catalyzed reductive carboxylation of benzylic C-N bonds with CO2 is described. This procedure outperforms state-of-the-art techniques for the carboxylation of benzyl electrophiles by avoiding commonly observed parasitic pathways, such as homodimerization or β-hydride elimination, thus leading to new knowledge in cross-electrophile reactions.

Nickel‐Catalyzed Enantioselective CC Bond Formation through C sp 2O Cleavage in Aryl Esters

We report the first enantioselective CC bond formation through CO bond cleavage using aryl ester counterparts. This method is characterized by its wide substrate scope and results in the formation of quaternary stereogenic centers with high yields and asymmetric induction.

Mild ArI-Catalyzed C(sp2)H or C(sp3)H Functionalization/CO Formation: An Intriguing Catalyst-Controlled Selectivity Switch†

A tandem C(sp(2))-H and C(sp(3))-H functionalization/C-O bond formation catalyzed by iodine(III) reagents generated in situ has been developed. The method shows wide scope under mild conditions and exhibits an unprecedented selectivity profile that can be switched depending on the catalyst employed.

Nickel‐Catalyzed Chemo‐, Regio‐ and Diastereoselective Bond Formation through Proximal CC Cleavage of Benzocyclobutenones

The first catalytic intermolecular proximal C1-C2 cleavage of benzocyclobutenones (BCB) without prior carbonyl activation or employing noble metals has been developed. This protocol operates at room temperature and is characterized by an exquisite chemo-, regio- and diastereoselectivity profile, constituting a unique platform for preparing an array of elusive carbocyclic skeletons.

Nickel-Catalyzed Reductive Amidation of Unactivated Alkyl Bromides

A user-friendly, nickel-catalyzed reductive amidation of unactivated primary, secondary, and tertiary alkyl bromides with isocyanates is described. This catalytic strategy offers an efficient synthesis of a wide range of aliphatic amides under mild conditions and with an excellent chemoselectivity profile while avoiding the use of stoichiometric and sensitive organometallic reagents.

Nickel‐Catalyzed Umpolung Arylation of Ambiphilic α‐Bromoalkyl Boronic Esters

A nickel-catalyzed reductive arylation of ambiphilic α-bromoalkyl boronic esters with aryl halides is described. This platform provides an unrecognized opportunity to promote the catalytic umpolung reactivity of ambiphilic reagents with aryl halides, thus unlocking a new cross-coupling strategy that complements existing methods for the preparation of densely functionalized alkyl-substituted organometallic reagents from simple and readily accessible precursors.

Ni-Catalyzed Silylation of Inert C-O Bonds under Mild Conditions

The pivotal role of arylsilanes as synthetic intermediates together with their use in medicinal chemistry and material science has attracted the attention and interest of the synthetic community. The synthesis of arylsilanes is typically accomplished via the reaction of stoichiometric and highly reactive organolithium or Grignard reagents with activated silicon sources (path a). Alternatively, aryl halides can be used as coupling partners (path b); however, the need for organic halides and the use of strongly reducing trialkylsilanes still constitute serious drawbacks when preparing backbones with sensitive functional groups. In recent years, the utilization of C-O electrophiles as coupling partners has received a great deal of attention due to their lack of toxicity and the readily availability of phenol as compared to commonly employed aryl halides as counterparts. While formidable advances have been realized in this area of expertise, to the best of our knowledge, the development of a catalytic C-Si bondforming event using simple and inert C-O bonds has no precedents in the literature. Herein, we report the success of this approach via Ni-catalyzed silylation of unactivated aryl esters via C-O bond-activation (path c).