Ni(II)-Catalyzed Asymmetric Nitration of Oxindoles: Construction of Cipargamin Analogues

Direct Synthesis of 2-Functionalized 3-Nitroindoles from Diazo(nitro)acetanilides

2-Hydroxyl/acetoxy-3-nitroindoles are directly and efficiently prepared in good to excellent yields from diazo(nitro)acetanilides under the catalysis of Cu(MeCN)4PF6 in DCM through an intramolecular aromatic C-H insertion or followed by acetylation. 2-Hydroxyl-3-nitroindoles can be further transformed to 3-halo-3-nitroindolin-2-ones and 3-alkanamidoindolin-2-ones readily. All of them are important synthetic building blocks for construction of indole derivatives.

Enantiocomplementary synthesis of β-adrenergic blocker precursors via biocatalytic nitration of phenyl glycidyl ethers

Enantiopure β-nitroalcohols, as an important class of nitro-containing compounds, are essential building blocks in pharmaceutical and organic chemistry, particularly for the synthesis of β-adrenergic blockers. In this study, we present the successful protein engineering of halohydrin dehalogenase HHDHamb for the enantioselective bio-nitration of various phenyl glycidyl ethers to the corresponding chiral β-nitroalcohols, using the inexpensive, commercially available, and safer nitrite as a nitrating agent. The chiral (R)- and (S)-1-nitro-3-phenoxypropan-2-ols were synthesized by the several enantiocomplementary HHDHamb variants through the whole-cell biotransformation, which showed good catalytic efficiency (up to 43% isolated yields) and high optical purity (up to >99% ee). In addition, we also demonstrated that the bio-nitration method was able to tolerate the substrate at a high concentration of 1000 mM (150 g/L). Furthermore, representative synthesis of two optically active enantiomers of the β-adrenergic blocker metoprolol was successfully achieved by utilizing the corresponding chiral β-nitroalcohols as precursors.

Recent Advances in the Enantioselective Radical Reactions

The review covers research published since 2017 and is focused on enantioselective synthesis using radical reactions. It describes recent approaches to the asymmetric synthesis of chiral molecules based on the application of the metal catalysis, dual metal and organocatalysis and finally, pure organocatalysis including enzyme catalysis. This review focuses on the synthetic aspects of the methodology and tries to show which compounds can be obtained in enantiomerically enriched forms.

Asymmetric β-Arylation of Cyclopropanols Enabled by Photoredox and Nickel Dual Catalysis

The enantioselective functionalization and transformation of readily available cyclopropyl compounds are synthetically appealing yet challenging topics in organic synthesis. Here we report an asymmetric β-arylation of cyclopropanols with aryl bromides...