Continuous flow synthesis of arylhydrazines via nickel/photoredox coupling of tert-butyl carbazate with aryl halides

Nickel/photoredox catalyzed C-N couplings of hydrazine-derived nucleophiles provide a powerful alternative to Pd-catalyzed methods. This continuous-flow photochemical protocol, optimized using design of experiments, achieves these couplings in short residence times, with high selectivity. A range of (hetero)aryl bromides and chlorides are compatible and understanding of process stability/reactor fouling has been discerned.

Highly Enantioselective One-Pot Synthesis of Chiral β-Heterosubstituted Alcohols via Ruthenium-Prolinamide-Catalyzed Asymmetric Transfer Hydrogenation

The utility of a chiral Ru-prolinamide catalytic system has been demonstrated in one-pot synthesis of optically active β-triazolylethanol and β-hydroxy sulfone derivatives. The said methodology proceeds through asymmetric transfer hydrogenation of in situ formed ketones of the corresponding chiral products. Various chiral prolinamide ligands were screened, and ligand L6 with isopropyl groups substituted at the ortho position has shown excellent activity at 60 °C in aqueous medium producing up to 95% yield and 99.9% enantioselectivity.

Exploiting Ancillary Ligation To Enable Nickel-Catalyzed C-O Cross-Couplings of Aryl Electrophiles with Aliphatic Alcohols

The use of (L)Ni( o-tolyl)Cl precatalysts (L = PAd-DalPhos or CyPAd-DalPhos) enables the C( sp²)-O cross-coupling of primary, secondary, or tertiary aliphatic alcohols with (hetero)aryl electrophiles, including unprecedented examples of such nickel-catalyzed transformations employing (hetero)aryl chlorides, sulfonates, and pivalates. In addition to offering a competitive alternative to palladium catalysis, this work establishes the feasibility of utilizing ancillary ligation as a complementary means of promoting challenging nickel-catalyzed C( sp²)-O cross-couplings, without recourse to precious-metal photoredox catalytic methods.

Switchable Synthesis of 3-Substituted 1H-Indazoles and 3,3-Disubstituted 3H-Indazole-3-phosphonates Tuned by Phosphoryl Groups

3-Alkyl/aryl-1H-indazoles and 3-alkyl/aryl-3H-indazole-3-phosphonates were synthesized efficiently through a 1,3-dipolar cycloaddition reaction between α-substituted α-diazomethylphosphonates and arynes under simple reaction conditions. The product distribution was controlled by the phosphoryl group, which acted both as a tuning group and a traceless group in the reaction.

New 2-(aryl/heteroaryl)-6-(morpholin-4-yl/pyrrolidin-1-yl)-(4-trifluoromethyl)quinolines: synthesis via Buchwald–Hartwig amination, photophysics, and biomolecular binding properties

New 6-(morpholino/pyrrolidino)quinolines displaying interesting photophysical and biomolecular binding properties achieved by Buchwald–Hartwig amination.