Catalytic enantioselective reductive desymmetrisation of achiral and meso compounds

Abstract

Herein an overview of reductive catalytic enantioselective desymmetrisation of achiral or meso compounds is provided. The most efficient reductive desymmetrisations described in the literature, which involve the reduction of C=O, C=N, C=C and C-halogen bonds, or reductive ring-opening, are summarised. The structural diversity of the valuable highly enantioenriched intermediates prepared by reductive desymmetrisation is highlighted.

Acyclic Quaternary Carbon Stereocenters via Enantioselective Transition Metal Catalysis

“…140–144 Such desymmetrization reactions have the advantage that creation of the quaternary center and the induction of chirality occur in separate events. While numerous desymmetrizing cyclizations have been developed, 144 the formation of acyclic quaternary carbon stereocenters through transition-metal catalyzed desymmetrization remains uncommon.…”

Organocatalytic enantioselective desymmetrisation

“…110 Acetal-tethered 1,3-diols underwent trans-acetalization in the presence of chiral phosphoric acid catalyst C-71 to furnish a range of aryl substituted THF derivatives (228)(229)(230)(231)(232)(233). 110 Acetal-tethered 1,3-diols underwent trans-acetalization in the presence of chiral phosphoric acid catalyst C-71 to furnish a range of aryl substituted THF derivatives (228)(229)(230)(231)(232)(233).…”

“…228 Bencivenni et al developed a remote control of axial chirality of succinimides containing a bulky ortho-tert-butylphenyl substituent on nitrogen using a cinchona alkaloid-derived primary amine. However, the use of organocatalysts with borane to enantioselectively reduce one imide carbonyl has been demonstrated.…”

Highly Enantioselective Ring‐Opening of meso‐Epoxides with O‐ and N‐Nucleophiles Catalyzed by a Chiral Sc(III)/bipyridine Complex

“…The meso-epoxides are inexpensive and readily available compounds that after catalytic enantioselective ring-opening give rise to enantiomerically enriched 1,2-difunctionalized building blocks. An array of C, N, O, S, Se, and halogen nucleophiles can be applied and synthesis of substances such as 1,2-cyanoalcohols, 1,2-azidoalcohols, 1,2-aminoalcohols, 1,2-diol monoesters and monoethers, mercaptoalcohols, and 1,2-halohydrins [10][11][12][13][14][15][16][17][18][19][20][21] have been achieved so far with good enantioselectivities. Chiral Lewis acids or bases usually catalyze such processes, and during the process, two enantiotopic carbon atoms of the epoxide moiety are differentiated by S N 2 nucleophilic attack at one of the epoxide carbon atoms.…”