Direct Enantioselective Three‐Component Kabachnik–Fields Reaction Catalyzed by Chiral Bis(imidazoline)‐Zinc(II) Catalysts

Abstract

A direct three‐component reaction of aldehydes, amines and diaryl phosphites was catalyzed by a zinc(II) complex of 1,3‐bis(imidazolin‐2‐ly)pyridine (pybim) giving the corresponding α‐aminophosphonates in good yield with good enantioselectivity. The reaction was applied to a wide variety of aromatic aldehydes to give products with excellent yields (up to 99%) and enantiomeric excesses (up to 93% ee).

Renoprotective effect of Tanshinone IIA, an active component of Salvia miltiorrhiza, on rats with chronic kidney disease

“…In the same year, Shibata et al. developed direct enantioselective three‐component Kabachnik–Fields reaction of aldehydes, p ‐aminophenol and diaryl phosphites catalyzed by a chiral zinc(II) complex of C 2 ‐symmetric pybim ligand 274 174. As shown in Scheme , a range of α‐aminophosphonates 275a – h could be achieved in almost quantitative yields in all cases of substrates studied and high enantioselectivities of up to 93% ee .…”

A New Procedure for Addition of Thiols to Imines using Zn[(L)‐Proline]2 as a Catalyst under Mild Conditions

“…So, we propose the plausible mechanism for the synthesis of N,S ‐acetals by using Zn( L ‐Pro) 2 as catalyst for thiol addition to N ‐Boc imine (Scheme ). Is noteworthy that this supposed mechanism is based on Oliveira and Shibata reports in which they described a zinc octahedral intermediate. Our conclusion relies on the intermediate 4.…”

Recent Developments in Enantioselective Metal‐Catalyzed Domino Reactions

“…In the same year, Shibata et al developed direct enantioselective three-component Kabachnik−Fields reaction of aldehydes, p-aminophenol and diarylphosphites catalyzed by a chiral zinc(II) complex of C 2symmetric pybim ligand 274. [174] As shown in Scheme 74, a range of -aminophosphonates 275a-h could be achieved in almost quantitative yields in all cases of substrates studied and high enantioselectivities of up to 93% ee. Although the scandium-catalyzed process described above by Feng et al employed a lower catalyst loading (5 mol% instead of 10 mol%) and a milder reaction temperature (-20°C instead of -50°C) to occur in comparison with this zinc-catalyzed process, the later provided both higher yields and enantioselectivities.…”