In:
Chirality, Wiley, Vol. 30, No. 4 ( 2018-04), p. 407-419
Abstract:
A few new d ‐mannitol‐based monoaza‐15‐crown‐5 type chiral lariat ethers and 18‐crown‐6 type macrocycles were synthesized. These crown compounds were used as phase transfer catalysts in asymmetric Michael addititons and in a Darzens condensation under mild conditions to afford the corresponding products in a few cases in good to excellent enantioselectivities. In the Michael addition of diethyl acetoxymalonate to trans ‐chalcone, in the addition of diethyl acetamidomalonate to ß ‐nitrostyrene, in the reaction of diethyl bromomalonate with benzylidene malononitriles, in the cyclopropanation reaction of diethyl bromomalonate and 2‐benzylidene‐1,3‐indandione, and in the Darzens condensation of α ‐chloroacetophenone with benzaldehyde, maximum enantioselectivities of 39%, 65%, 99%, 56%, and 62%, respectively, were obtained in the presence of the d ‐mannitol‐based macrocycles as the catalysts.
Type of Medium:
Online Resource
ISSN:
0899-0042
,
1520-636X
Language:
English
Publisher:
Wiley
Publication Date:
2018
detail.hit.zdb_id:
2001237-8
SSG:
12
SSG:
15,3
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