Synthesis, characterization and first application of chiral C₂‐symmetric bis(phosphinite)–Pd(II) complexes as catalysts in asymmetric intermolecular Heck reactions

Abstract

A series of new chiral C 2 -symmetric bis(phosphinite) ligands and their palladium(II) complexes have been synthesized and for the first time used as catalysts in the palladium-catalysed asymmetric intermolecular Heck coupling reactions of 2,3-dihydrofuran with iodobenzene or aryl triflate. Under optimized conditions, products were obtained with high conversions and moderate to good enantioselectivities. The new C 2 -symmetric bis(phosphinite) ligands and their palladium(II) complexes were characterized using multinuclear NMR and Fourier transform infrared spectroscopies and elemental analysis.

Easily fabricated and recyclable Pd&Cu@Al catalyst for gram-scale phosphine-free Heck reactions with high TON

“…On the other hand, as a powerful tool in organic synthesis [7][8][9][10][11][12][13], the Heck reaction has been widely adopted in alkene modification to construct useful organic skeletons and applied in natural product synthesis, medicinal chemistry, and even materials science [14][15][16][17][18][19][20]. During the past decades, organic chemists have developed a series of effective catalyst systems for the Heck reaction to address a variety of challenges in their researches, such as the sp 3 C-X bond activation [21][22][23][24], asymmetric synthesis [25][26][27], tandem reactions with high stereoselectivity [28,29], etc. However, most methods require the use of phosphine ligands to activate the metal catalysts, but the disadvantages of using phosphine ligands are also well-known.…”