Palladium-Catalyzed Regioselective Diarylation/Deamination of Homoallylamines: Modular Assembly of 1,1,4,4-Tetraaryl-1,3-butadienes.

Herein, a novel palladium-catalyzed regioselective diarylation/deamination of homoallylamines is described. During the process, a ubiquitous free amine (NH) was used as the directing group to accomplish the regioselective δ,δ-diarylation and it was removed in situ to form the privileged 1,1,4,4-tetraaryl-1,3-butadiene motif. This chelate-controlled Heck-type approach eliminates the traditional need of preinstalled and hard removable directing groups, proceeds under simple conditions, and exhibits good tolerance to a wide range of synthetically useful functional groups.

A Radical Addition/Cyclization and Se-Group Transfer Strategy for the Facile Synthesis of Se-Containing Cyclopentenes under Metal-Free and Peroxide-Free Conditions.

A novel intermolecular radical addition/cyclization and Se-group transfer reaction of terminal alkynes and unsaturated alkyl selenide is presented which offers a straightforward and facile approach for the synthesis of valuable Se-containing cyclopentenes. Remarkable features of this strategy include easily accessible starting materials, metal-free and peroxide-free conditions, high atom economy, simple operation and broad substrate scope. More importantly, the reaction is easy to scale up and can be extended to the construction of six-membered carbon ring.

Divergent synthesis of α-functionalized amides through selective N-O/C-C or N-O/C-C/C-N cleavage of aza-cyclobutanone oxime esters.

Herein, a novel sequential ring opening reaction of aza-cyclobutanone oxime esters with isocyanides is described. The reaction proceeded smoothly under redox-neutral and mild conditions, leading to a divergent synthesis of α-cyanomethylaminoamides, α-acyloxyamides and α-acylaminoamides. In these transformations, a selective N-O/C-C or N-O/C-C/C-N cleavage was achieved only by changing the iron-catalyst system.

Amidation-Ketonization-Selenation of Terminal Alkynes Using TEMPO and Elemental Selenium.

Herein, we present a novel silver- or copper-mediated direct amidation-ketonization-selenation of terminal alkynes for the synthesis of α-oxo-selenoamides. The reaction utilized easily accessible elemental selenium as the source of selenium. In addition, the O labeling experiment revealed that TEMPO is the oxygen source of the carbonyl group.