TY - JOUR

T1 - Role of Association in Chiral Catalysis

T2 - From Asymmetric Synthesis to Spin Selectivity

AU - Ageeva, Aleksandra A.

AU - Khramtsova, Ekaterina A.

AU - Magin, Ilya M.

AU - Purtov, Peter A.

AU - Miranda, Miguel A.

AU - Leshina, Tatyana V.

N1 - © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

PY - 2018/12/12

Y1 - 2018/12/12

N2 - The origin of biomolecules in the pre-biological period is still a matter of debate, as is the unclarified nature of the differences in enantiomer properties, especially for the medically important activity of chiral drugs. With regards to the first issue, significant progress was made in the last decade of the 20th century through experimental confirmation of Frank's popular theory on chiral catalysis in spontaneous asymmetric synthesis. Soai examined the chiral catalysis of the alkylation of achiral aldehydes by achiral reagents. Attempts to model this process demonstrated the key role of chiral compounds associates as templates for chiral synthesis. However, the elementary mechanism of alkylation and the role of free radicals in this process are still incompletely understood. Meanwhile, the influence of external magnetic fields on chiral enrichment in the radical path of alkylation has been predicted. In addition, the role of chiral dyad association in another radical process, electron transfer (ET), has been recently demonstrated by the following methods: chemically induced dynamic nuclear polarisation (CIDNP), NMR spectroscopy, XRD and photochemistry. The CIDNP analysis of ET in two dyads has revealed a phenomenon first observed for chiral systems, spin selectivity, which results in the difference between the CIDNP enhancement coefficients of dyad diastereomers. These dyads are linked systems consisting of the widespread drug (S)-naproxen (NPX) or its R analogue and electron donors, namely, (S)-tryptophan and (S)-N-methylpyrrolidine. Because NPX is one of the most striking examples of the difference in the therapeutic properties of enantiomers, the appearance of spin selectivity in dyads with (S)- and (R)-NPX and S donors can shed light on the chemical nature of these differences. This review is devoted to discussing the chemical nature of spin selectivity and the role of chiral associates in the chiral catalysis of an elementary radical reaction: ET in chiral dyads.

AB - The origin of biomolecules in the pre-biological period is still a matter of debate, as is the unclarified nature of the differences in enantiomer properties, especially for the medically important activity of chiral drugs. With regards to the first issue, significant progress was made in the last decade of the 20th century through experimental confirmation of Frank's popular theory on chiral catalysis in spontaneous asymmetric synthesis. Soai examined the chiral catalysis of the alkylation of achiral aldehydes by achiral reagents. Attempts to model this process demonstrated the key role of chiral compounds associates as templates for chiral synthesis. However, the elementary mechanism of alkylation and the role of free radicals in this process are still incompletely understood. Meanwhile, the influence of external magnetic fields on chiral enrichment in the radical path of alkylation has been predicted. In addition, the role of chiral dyad association in another radical process, electron transfer (ET), has been recently demonstrated by the following methods: chemically induced dynamic nuclear polarisation (CIDNP), NMR spectroscopy, XRD and photochemistry. The CIDNP analysis of ET in two dyads has revealed a phenomenon first observed for chiral systems, spin selectivity, which results in the difference between the CIDNP enhancement coefficients of dyad diastereomers. These dyads are linked systems consisting of the widespread drug (S)-naproxen (NPX) or its R analogue and electron donors, namely, (S)-tryptophan and (S)-N-methylpyrrolidine. Because NPX is one of the most striking examples of the difference in the therapeutic properties of enantiomers, the appearance of spin selectivity in dyads with (S)- and (R)-NPX and S donors can shed light on the chemical nature of these differences. This review is devoted to discussing the chemical nature of spin selectivity and the role of chiral associates in the chiral catalysis of an elementary radical reaction: ET in chiral dyads.

KW - asymmetric catalysis

KW - chirality

KW - electron transfer

KW - enantioselectivity

KW - spin selectivity

KW - FIELDS

KW - ALKOXIDE

KW - SINGLE-ELECTRON-TRANSFER

KW - PYRIMIDYL ALKANOL

KW - RECOGNITION

KW - EPR

KW - QUANTIFICATION

KW - AUTOCATALYSIS

KW - NMR

KW - HOMOCHIRAL SUPRAMOLECULAR POLYMERIZATION

UR - http://www.scopus.com/inward/record.url?scp=85055747739&partnerID=8YFLogxK

UR - https://www.mendeley.com/catalogue/9fee2a07-393e-3a16-affb-13c1973fb6c1/

U2 - 10.1002/chem.201801625

DO - 10.1002/chem.201801625

M3 - Review article

C2 - 29932476

AN - SCOPUS:85055747739

VL - 24

SP - 18587

EP - 18600

JO - Chemistry - A European Journal

JF - Chemistry - A European Journal

SN - 0947-6539

IS - 70

ER -