Tail‐Tied Ligands: An Immobilized Analogue of (R)‐2‐Piperidino‐1,1,2‐triphenylethanol with Intact High Catalytic Activity and Enantioselectivity

Abstract

A functional analogue of (R)-2-piperidino-1,1,2-triphenylethanol was synthesized and anchored to different polymeric supports by a position remote from the active region. This strategy, leading to what we call a tail-tied ligand, allows for the achievement of the optimal transition state geometry in the catalytic process. The catalytic activity of the resulting heterogenized ligands was investigated by online FTIR analysis. The optimum polymer was assayed in the addition reaction of diethylzinc to a large family of aldehydes rendering essentially intact high catalytic activity and enantioselectivity compared to its homogeneous counterpart.

Sunlight‐Driven Synthesis of Triarylethylenes (TAEs) via Metal‐Free Mizoroki–Heck‐Type Coupling

“…[27a] 110 °C, 80 % yield). Spectroscopic data of 2a were in accordance with the literature . The same process was carried out by exposing the reaction mixture to natural sunlight for 2 d (6 h/day).…”

Stereoselective Synthesis and Modelling‐Driven Optimisation of Carane‐Based Aminodiols and 1,3‐Oxazines as Catalysts for the Enantioselective Addition of Diethylzinc to Benzaldehyde

“…Chiral 3‐amino‐1,2‐diols, which combine the chemical properties of 1,2‐ and 1,3‐amino alcohols, have also been widely used as chiral auxiliaries or chiral ligands in enantioselective syntheses …”

“…[4,[9][10][11] Chiral 3-amino-1,2-diols,w hich combine the chemical properties of 1,2-and 1,3-amino alcohols, have also been widely used as chiral auxiliaries or chiral ligandsi ne nantioselective syntheses. [12][13][14][15][16][17][18][19][20] Moreover,3 -amino-1,2-diols are excellent building blocks for the synthesis of versatile heterocyclic compounds:d epending upon which hydroxy group undergoes ring closurew ith the aminog roup, af ive-to as even-membered ring may be formed stereoselectively. [21][22][23][24] The presence of ac oordinative hydroxy group in the resulting heterocyclesm ay give rise to greater rigidity within at ransition state, and hence highere nantioselective induction in asymmetrict ransformations.…”

Enantioselective Continuous‐Flow Production of 3‐Indolylmethanamines Mediated by an Immobilized Phosphoric Acid Catalyst

“…From previous experience in our laboratory, we planned to immobilize at a remote position to avoid perturbation of the active site of the catalyst. [11] (R)-6-Hydroxymethyl-2,2'-bis(methoxymethyloxy)-1,1'-binaphthalene (1) was synthesized from commercially available (R)-BINOL by a reported procedure. [12] Compound 1 was converted to the 6-hydroxymethyl derivative 5 in four steps and, subsequently, this monomer was anchored onto a Merrifield resin by nucleophilic substitution of the chlorine atoms (Scheme 2).…”

“…From previous experience in our laboratory, we planned to immobilize at a remote position to avoid perturbation of the active site of the catalyst 11. ( R )‐6‐Hydroxymethyl‐ 2,2’‐bis(methoxymethyloxy)‐1,1’‐binaphthalene ( 1 ) was synthesized from commercially available ( R )‐BINOL by a reported procedure 12.…”