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ChemInform Abstract: Asymmetric Alkylation of Aromatic Aldehydes with Dialkylzinc Catalyzed by Novel Amino Derivatives of Hydroxytetrahydropyran.

✍ Scribed by Guenther Oehme; Irina Lovel; Edmunds Lukevics

Publisher
John Wiley and Sons
Year
2010
Weight
32 KB
Volume
30
Category
Article
ISSN
0931-7597

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✦ Synopsis

Asymmetric Alkylation of Aromatic Aldehydes with Dialkylzinc

Catalyzed by Novel Amino Derivatives of Hydroxytetrahydropyran.

-The asymmetric addition of dialkylzinc reagents (III) and (V) to aromatic aldehydes proceeds with varying selectivities depending on the catalyst used. Dibutylnorephedrine (DBNE) affords (S)-1-phenylalkanols in high yields and stereoselectivity. In contrast, the novel chiral tetrahydropyranbased 1,3-aminoalcohols (I) selectively provide (R)-alcohols in optical purities strongly depending on the substitution pattern of catalysts (I). Thus, phenoxysubstituted tetrahydropyrans are more reactive than ethoxy analogues, and cyclic secondary amine groups (especially pyrrolidine group) provide higher catalytic activity than acyclic analogues. The highest asymmetric induction is achieved using catalyst (Id).

πŸ“œ SIMILAR VOLUMES

Asymmetric alkylation of aromatic aldehy
Asymmetric alkylation of aromatic aldehydes with dialkylzinc catalyzed by novel amino derivatives of hydroxytetrahydropyran
✍ GΓΌnther Oehme; Irina Iovel; Edmunds Lukevics πŸ“‚ Article πŸ“… 1999 πŸ› John Wiley and Sons 🌐 English βš– 56 KB πŸ‘ 2 views

Novel, specially prepared, tetrahydropyranbased g-amino alcohols (S)-2-(aminomethyl)-3-hydroxy-6-ethoxy(phenoxy)-tetrahydropyrans (I) (amino = n-Bu 2 N, piperidinyl, pyrrolidinyl, azetidinyl) were tested as catalysts in the asymmetric addition of Et 2 Zn and n-Bu 2 Zn to (hetero)aromatic aldehydes.