Triple-Consecutive Isocyanide Insertions with Aldehydes: Synthesis of 4‑Cyanooxazoles

An efficient TMSOTf-promoted selective triple consecutive insertions of tert-butyl isocyanide into aldehydes has been developed, affording pharmacological interesting 4-cyanooxazoles in high yields in a one pot manner. The given method encompasses a wide range of substrates with tert-butyl isocyanide serving as sources of critical “CN” and “C–NC” moieties. The versatile transformations of the resulting 4-cyanooxazoles were demonstrated. The key reaction intermediates for plausible mechanisms were determined

Pyridine-NHC: Effective Ligand in Pd-Catalyzed Cyclopropanation of Esters with Substituted Allyl Carbonates

By consideration of the mechanism of Pd-catalyzed cyclopropanation and allylation, NHC-pyridine compounds were adopted as the ligand in Pd-catalyzed cyclopropanation of esters and monosubstituted allylic reagents. The corresponding cyclopropanes were afforded as major products in moderate to good yields with high cyclopropane/allylation selectivity

Pyridine-NHC: Effective Ligand in Pd-Catalyzed Cyclopropanation of Esters with Substituted Allyl Carbonates

By consideration of the mechanism of Pd-catalyzed cyclopropanation and allylation, NHC-pyridine compounds were adopted as the ligand in Pd-catalyzed cyclopropanation of esters and monosubstituted allylic reagents. The corresponding cyclopropanes were afforded as major products in moderate to good yields with high cyclopropane/allylation selectivity

Pyridine-NHC: Effective Ligand in Pd-Catalyzed Cyclopropanation of Esters with Substituted Allyl Carbonates

By consideration of the mechanism of Pd-catalyzed cyclopropanation and allylation, NHC-pyridine compounds were adopted as the ligand in Pd-catalyzed cyclopropanation of esters and monosubstituted allylic reagents. The corresponding cyclopropanes were afforded as major products in moderate to good yields with high cyclopropane/allylation selectivity

Diastereo- and Enantioselective Synthesis of α,γ-Diaminobutyric Acid Derivatives via Cu-Catalyzed Asymmetric Michael Reaction

The first highly diastereo- and enantioselective catalytic asymmetric Michael addition of glycine derivatives to nitroalkenes have been developed. The enantioselectivity of ortho-substituted products can be significantly improved by using a new 1,2-P,N-ferrocene ligand L5. The α,γ-diaminoacid derivative was obtained without the loss of optical activity from the adduct

Diastereo- and Enantioselective Synthesis of α,γ-Diaminobutyric Acid Derivatives via Cu-Catalyzed Asymmetric Michael Reaction

The first highly diastereo- and enantioselective catalytic asymmetric Michael addition of glycine derivatives to nitroalkenes have been developed. The enantioselectivity of ortho-substituted products can be significantly improved by using a new 1,2-P,N-ferrocene ligand L5. The α,γ-diaminoacid derivative was obtained without the loss of optical activity from the adduct

Silver-Assisted Oxidative Isocyanide Insertion of Ethers: A Direct Approach to β‑Carbonyl α‑Iminonitriles

An efficient silver-assisted oxidative coupling of simple ethers with tert-butyl isocyanide was realized in the presence of DDQ. The direct synthesis of high density functional β-carbonyl α-iminonitriles was achieved in a single step with high yields through the synergetic cascade isocyanide insertion into C­(sp3)–H bond, where the isocyanide was used as crucial “CN” and “CN” sources and the tert-butoxyl group acted as the carbonyl source. Diverse reactivity of β-carbonyl α-iminonitriles has been demonstrated

Ag-Catalyzed Diastereo- and Enantioselective Synthesis of β-Substituted Tryptophans from Sulfonylindoles

The asymmetric catalytic synthesis of β-substituted tryptophan derivatives was realized in high diastereo- and enantioselectivity by the reaction of glycine derivatives with sulfonylindoles in the presence of catalyst derived from AgCl and a commercially available chiral monodentate phosphoramidite ligand. The resulting adduct was readily converted to β-substituted tryptophan in 95% overall yield for two steps, which presented a highly efficient route to chiral β-substituted tryptophan

Enantioselective Synthesis of 2,3-Disubstituted Indanones via Pd-Catalyzed Intramolecular Asymmetric Allylic Alkylation of Ketones

A Pd-catalyzed intramolecular asymmetric allylic alkylation (AAA) reaction with “hard” carbanions has been developed for the first time, affording 2,3-disubstituted indanones with high diastereo- and enantioselectivities. The transformation of these products into other core structures of natural products has been demonstrated

Ag-Catalyzed Diastereo- and Enantioselective Synthesis of β-Substituted Tryptophans from Sulfonylindoles

The asymmetric catalytic synthesis of β-substituted tryptophan derivatives was realized in high diastereo- and enantioselectivity by the reaction of glycine derivatives with sulfonylindoles in the presence of catalyst derived from AgCl and a commercially available chiral monodentate phosphoramidite ligand. The resulting adduct was readily converted to β-substituted tryptophan in 95% overall yield for two steps, which presented a highly efficient route to chiral β-substituted tryptophan