C–H activation has surfaced as an increasingly powerful tool for molecular sciences, with notable applications to material sciences, crop protection, drug discovery, and pharmaceutical industries, among others. Despite major advances, the vast majority of these C–H functionalizations required precious 4d or 5d transition metal catalysts. Given the cost-effective and sustainable nature of earth-abundant first row transition metals, the development of less toxic, inexpensive 3d metal catalysts for C–H activation has gained considerable recent momentum as a significantly more environmentally-benign and economically-attractive alternative. Herein, we provide a comprehensive overview on first row transition metal catalysts for C–H activation until summer 2018.

3d Transition Metals for C-H Activation.

Complete Field Guide to Asymmetric BINOL-Phosphate Derived Brønsted Acid and Metal Catalysis: History and Classification by Mode of Activation; Brønsted Acidity, Hydrogen Bonding, Ion Pairing, and Metal Phosphates

3.10 - Nitroxide-Mediated Polymerization

10.2. Synthesis of Other -Amino Acid Derivatives 3676 10.2.1. Synthesis of -Amino Ketones 3676 10.2.2. Synthesis of -Amino Nitriles 3679 10.2.3. Synthesis of -Amino Phosphinates 3680 10.2.4. Synthesis of -Amino Sulfonates 3681 11. Synthesis of 1,2-Amino Alcohols 3681 11.1. 1,2-Addition to R-Alkoxy Imines 3681 11.2. 1,2-Addition of R-Substituted Organometallic Reagents to N-tert-Butanesulfinyl Imines 3687 * E-mail: jellman@berkeley.edu. † These authors contributed equally to this work. Chem. Rev. 2010, 110, 3600–3740 3600

Synthesis and Applications of tert-Butanesulfinamide

Catalytic C-C bond-forming multi-component cascade or domino reactions: pushing the boundaries of complexity in asymmetric organocatalysis.

Oxidative homocoupling of aryl, alkenyl, and alkynyl Grignard reagents with TEMPO and dioxygen.

Asymmetric Brønsted acid catalyzed cycloadditions--efficient enantioselective synthesis of pyrazolidines, pyrazolines, and 1,3-diamines from N-acyl hyrazones and alkenes.

Bronsted acid catalyzed (3+ + 2) cycloadditions between hydrazones and alkenes provide a general approach to pyrazolidines. The acidity of the Bronsted acid is crucial for the catalytic efficiency: the less acidic phosphoric acids are ineffective, while highly acidic chiral N-triflylphosphoramides are very efficient and can promote highly enantioselective cycloadditions. The mechanism and origins of catalytic efficiencies and selectivities of these reactions have been explored with density functional theory (M06-2X) calculations. Protonation of hydrazones by N-triflylphosphoramide produces hydrazonium–phosphoramide anion complexes. These ion-pair complexes are very reactive in (3+ + 2) cycloadditions with alkenes, producing pyrazolidine products. Alternative 1,3-dipolar (3 + 2) cycloadditions with the analogous azomethine imines are much less favorable due to the endergonic isomerization of hydrazone to azomethine imine. With N-triflylphosphoramide catalyst, only a small distortion of the ion-pair complex...

Mechanism and Selectivity of N-Triflylphosphoramide Catalyzed (3+ + 2) Cycloaddition between Hydrazones and Alkenes

Weakly Coordinating, Ketone-Directed Cp*Co(III)-Catalyzed C–H Allylation on Arenes and Indoles

Catalytic fluorolactonisations of aromatic carboxylic acids have been developed. The reactions proceed under mild conditions using the commercially available reagent Selectfluor. A weak phase transfer of the reagent mediated by Na2CO3 allows the reaction to be conducted in non-polar solvents. Furthermore, by the use of a catalytic amount of (DHQ)2PHAL (hydroquinine 1,4-phthalazinediyl diether), the first asymmetric fluorolactonisation has been achieved. The corresponding isobenzofuran core can be found in many biologically active molecules.

Modhu Sudan Maji

Papers

Oxidative homocoupling of aryl, alkenyl, and alkynyl Grignard reagents with TEMPO and dioxygen.

Asymmetric Brønsted acid catalyzed cycloadditions--efficient enantioselective synthesis of pyrazolidines, pyrazolines, and 1,3-diamines from N-acyl hyrazones and alkenes.

Mechanism and Selectivity of N-Triflylphosphoramide Catalyzed (3+ + 2) Cycloaddition between Hydrazones and Alkenes

Weakly Coordinating, Ketone-Directed Cp*Co(III)-Catalyzed C–H Allylation on Arenes and Indoles

Catalytic and Asymmetric Fluorolactonisations of Carboxylic Acids through Anion Phase Transfer