O-Mediated Cu-Catalyzed Dehydrogenative Phenothiazination.

In contrast to what one can be led to believe upon inspecting some of the recent literature, the dehydrogenative phenothiazination reaction does not require onerous technologies, complicated setups, or advanced catalysts in order to be mild and sustainable. We demonstrate this herein with a most facile, cost-effective, and sustainable Cu(II) catalyzed method, under 1 atm of O at room temperature in methanol, providing broad scope and high yields. These new results further set the dehydrogenative phenothiazination reaction among the green and practical coupling concepts of chemistry.

Pd-catalyzed access to mono- and di-fluoroallylic amines from primary anilines.

The Pd-catalyzed highly selective synthesis of mono- and di-2-fluoroallylic amines from -difluorocyclopropanes and ubiquitous unprotected primary anilines is herein described. Initial kinetic investigations suggest a first order in the -difluorocyclopropane substrate, as well as a zeroth order in the aniline coupling partner. The newly produced fluoroallylic motifs should find important applications in synthetic as well as medicinal chemistry and stimulate the further development of coupling methods based on strained cyclic building blocks.

Phosphine-Catalyzed Dearomative [3 + 2] Cycloaddition of Benzoxazoles with a Cyclopropenone.

The triphenylphosphine-catalyzed dearomative [3 + 2] cycloaddition of benzoxazoles with 1,2-diphenylcyclopropenone is herein described. The reaction scope, mechanism, and possible future applications of this rare organocatalyzed cycloaddition are herein discussed.

Stereospecific Si-C coupling and remote control of axial chirality by enantioselective palladium-catalyzed hydrosilylation of maleimides.

Hydrosilylation of unsaturated carbon-carbon bonds with hydrosilanes is a very important process to access organosilicon compounds and ranks as one of the most fundamental reactions in organic chemistry. However, catalytic asymmetric hydrosilylation of activated alkenes and internal alkenes has proven elusive, due to competing reduction of carbon-carbon double bond or isomerization processes. Herein, we report a highly enantioselective Si-C coupling by hydrosilylation of carbonyl-activated alkenes using a palladium catalyst with a chiral TADDOL-derived phosphoramidite ligand, which inhibits O-hydrosilylation/olefin reduction.

Controllable Si-C Bond Activation Enables Stereocontrol in the Palladium-Catalyzed [4+2] Annulation of Cyclopropenes with Benzosilacyclobutanes.

A novel and unusual palladium-catalyzed [4+2] annulation of cyclopropenes with benzosilacyclobutanes is reported. This reaction occurred through chemoselective Si-C(sp ) bond activation in synergy with ring expansion/insertion of cyclopropenes to form new C(sp )-C(sp ) and Si-C(sp ) bonds. An array of previously elusive bicyclic skeleton with high strain, silabicyclo[4.

Enantioselective Cross-Exchange between C-I and C-C σ Bonds.

A palladium-catalyzed enantioselective intramolecular σ-bond cross-exchange between C-I and C-C bonds is realized, providing chiral indanones bearing an alkyl iodide group and an all-carbon quaternary stereocenter. Pd/TADDOL-derived phosphoramidite is found to be an efficient catalytic system for both C-C bond cleavage and alkyl iodide reductive elimination. In addition to aryl iodides, aryl bromides can also be used for this transformation in the presence of KI.

Palladium-catalyzed olefination of aryl/alkyl halides with trimethylsilyldiazomethane via carbene migratory insertion.

The direct olefination of aryl/alkyl halides with trimethylsilyldiazomethane (TMSD) as a C1- or C2-unit was achieved successfully via a metal carbene migratory insertion process, which offered a new access to afford (E)-vinyl silanes and (E)-silyl-substituted α,β-unsaturated amides in good yields and high chemoselectivity.