Cu-catalyzed C(sp)-N-bond coupling of boronic acids and cyclic imides.

A general Cu-catalyzed strategy for coupling cyclic imides and alkenylboronic acids by forming C(sp)N-bonds is reported. The method enables the practical and mild preparation of ()-enimides. A large range of cyclic imides are allowed, and di- and tri-substituted alkenylboronic acids can be used.

Cu-catalyzed -3-Arylation of Hydantoins Using Diaryliodonium Salts.

A general Cu-catalyzed, regioselective method for the -3-arylation of hydantoins is described. The protocol utilizes aryl(trimethoxyphenyl)iodonium tosylate as the arylating agent in the presence of triethylamine and a catalytic amount of a simple Cu-salt. The method is compatible with structurally diverse hydantoins and operates well with neutral aryl groups or aryl groups bearing weakly donating/withdrawing elements.

Imide arylation with aryl(TMP)iodonium tosylates.

Herein, we describe the synthesis of -aryl phthalimides by metal-free coupling of potassium phthalimide with unsymmetrical aryl(TMP)iodonium tosylate salts. The aryl transfer from the iodonium moiety occurs under electronic control with the electron-rich trimethoxyphenyl group acting as a competent dummy ligand. The yields of -aryl phthalimides are moderate to high and the coupling reaction is compatible with electron-deficient and sterically encumbered aryl groups.

Investigating Biogenetic Hypotheses of the Securinega Alkaloids: Enantioselective Total Syntheses of Secu'amamine E/ent-Virosine A and Bubbialine.

The synthesis of the Securinega alkaloid secu'amamine E (ent-virosine A) has been accomplished for the first time in 12 steps and 8.5% overall yield. In addition, bubbialine has been prepared and characterized.

Synthesis of Aryl(2,4,6-trimethoxyphenyl)iodonium Trifluoroacetate Salts.

The direct synthesis of aryl(2,4,6-trimethoxyphenyl)iodonium trifluoroacetate salts from aryl iodides is described. Stoichiometric quantities of trifluoroacetic acid and trimethoxybenzene are used as the counteranion and auxiliary precursors, respectively, under oxidizing conditions. The reaction occurs at mild temperature, is broad in scope, and does not require a separate anion exchange step to install the trifluoroacetate group.

Metal-free Synthesis of Aryl Amines: Beyond Nucleophilic Aromatic Substitution.

A mild and metal-free approach to C-N coupling is described that employs diaryliodonium salt electrophiles and secondary aliphatic amine nucleophiles. This reaction results in direct ipso-substitution of the iodonium moiety and unsymmetrical aryl(TMP)iodonium salts are primarily employed. Moreover, arene substituents and substitution patterns that currently pose a challenge to classical metal-free methods are accommodated and the alicyclic amine nucleophiles used here are unprecedented in other contemporary metal-free C-N coupling reactions.

4-Alkylated Silver-N-Heterocyclic Carbene (NHC) Complexes with Cytotoxic Effects in Leukemia Cells.

Computational chemistry has shown that backbone-alkylated imidazoles ought to be efficient ligands for transition metal catalysts with improved carbene-to-metal donation. In this work, such alkylated imidazoles were synthesized and complexed with silver(I) by means of an eight/nine-step synthetic pathway we devised to access a new class of biologically active silver complexes. The synthesis involves selective iodination of the imidazole backbone, followed by Sonogashira coupling to replace the backbone iodine.