Enantioselective Heck Reactions Catalyzed by Chiral Phosphinooxazoline-Palladium Complexes

Comparative Study of 1,5‐Dinitrogen Schiff Bases as Potential Ligands in Palladium‐Catalyzed Allylic Alkylation.

“…On cooling CH 2 Cl 2 (5.0 ml) was added, and reaction solution washed with std. aqueous NH 4 Cl solution (5.0 ml). Organic phase was dried, solvent removed and crude product purified by flash chromatography on 30 g silica gel, with n-hexane/i-Pr 2 O (5:2) as eluent.…”

“…Compound 6 (172 mg, 0.56 mmol), (R)-1-phenylethylamine (80 mg, 0.67 mmol), and Si(OEt) 4 (208 mg, 1.0 mmol) were deaerated in toluene (2.0 ml), filtered over basic aluminum oxide, activity I, and then heated in the sealed glass tube at 160°C over 66 h. To the cooled reaction mixture CH 2 Cl 2 (20 ml) was added, and resulting mixture washed with aq. bicarbonate solution.…”

“…Chiral bidentate nitrogen ligands proved highly efficient in a various homogeneous catalytic processes; such as hydrosylilation of ketones, 1 cyclopropanation of alkenes, 2 Diels-Alder reaction, 3 Heck reaction, 4 allylic aminations, 5 and allylic alkylations. [6][7][8][9][10] Recent papers have confirmed versatility of the asymmetric allylic alkylation, Scheme 1, 6 as the synthetic procedure for enantioselective formation of C-C bond in acyclic [11][12][13][14][15] and cyclic 16 substrates, or in its intramolecular variant.…”

“…During usual workup all organic extracts were dried over Na 2 SO 4 or MgSO 4 and evaporated in vacuo on a Büchi rotavapor.…”

Synthesis of New Chiral Bidentate (Phosphinophenyl)benzoxazine P,N-Ligands

“…± Bidentate chiral dihydro(phosphinoaryl)oxazole ligands 1 are readily obtained from 2-aminoalkan-1-ols. They have been applied highly successfully in a number of catalytic reactions including allylic substitution [1], Heck reaction [2], hydrogenation [3], hydrosilylation [4], and Diels-Alder reaction [5]. Given the success and popularity of ligands 1, it is surprising that the use of the six-membered analogues is scarce [6].…”