ROS , Abel

The dynamic kinetic Pd0 -catalyzed alkynylation of racemic heterobiaryl sulfonates was used for the asymmetric synthesis of axially chiral heterobiaryl alkynes with a broad scope. The use of Pd(OAc)2/ (S)-QUINAP as the precatalyst provides products in excellent yields and enantioselectivities under mild conditions (DMSO, 40 8C). Semireduction,...

The Pd-catalyzed coupling of racemic heterobiaryl bromides, triflates, or nonaflates with aryl/alkyl primary amines using QUINAP as the ligand provides the corresponding axially chiral heterobiaryl amines with excellent yields and enantioselectivities. Reactivity and structural studies of neutral and cationic oxidative addition intermediates...

The Pd-catalyzed enantioselective C-P cross-coupling between racemic, configurationally stable heterobiaryl triflates and trialkylsilyldiaryl(dialkyl)phosphines has been used for the synthesis of several families of enantiomerically enriched heterobiaryl phosphines including QUINAP, PINAP, and QUINAZOLINAP analogues, which can be performed with...

A highly regio-, diastereo-, and enantioselective, scalable Ir-catalyzed hydroarylation of electron-rich acyclic and tensioned cyclic olefins with heterobiaryls is described. The reaction of acyclic vinyl ethers, dihydrofuran, and norbornenes with a variety of aryl isoquinoline, quinazoline, and picoline derivatives takes place with...

The geometries and coordination properties of modular pyridineehydrazone N,N-ligands containing C2- symmetric trans-2,5-diphenylpyrrolidine and trans-2,5-diphenylpiperidine as the terminal dialkylamino units have been analyzed by X-ray diffraction analysis of [PdCl2(N,N)] complexes [(N,N)¼pyridine hy- drazone ligand]. In combination with...

A dynamic kinetic asymmetric Pd-catalyzed cross-coupling reaction of heterobiaryl bromides with ketone N-tosylhydrazones for the synthesis of heterobiaryl styrenes is described. The combination of Pd(dba)2 as a precatalyst with a TADDOL-derived phosphoramidite ligand provides the corresponding coupling products in good yields and high...

Seven tetracoordinate organoboron fluorophores with heterobiaryl N,O- or N,N-chelate ligands were prepared and photophysically characterized (in toluene). The electronic variation of the heteroaromatic moiety provided a means for the fine-tuning of the UV/vis absorption and emission spectra. In the most interesting cases, the spectra were...