A highly enantioselective approach towards optically active γ-amino alcohols by tin-catalyzed kinetic resolution of 1,3-amino alcohols
作者:Jian Song、Wen-Hua Zheng
DOI:10.1039/d2cc01963a
日期:——
A highlyenantioselective kinetic resolution of racemic 1,3-amino alcohols via O-Acylation was achieved using a chiral organotin as the catalyst. Alkyl- and aryl-substituted 1,3-amino alcohols were resolved with excellent efficiencies to afford the recovered 1,3-amino alcohols and acylative products with high enantioselectivities, with s factors up to >600. Notably, the chiral organotin catalyst was
Lewis acid mediated SN2-type nucleophilic ring opening followed by [4+2] cycloaddition of N-tosylazetidines with aldehydes and ketones: synthesis of chiral 1,3-oxazinanes and 1,3-amino alcohols
作者:Manas K. Ghorai、Kalpataru Das、Amit Kumar
DOI:10.1016/j.tetlet.2007.04.097
日期:2007.6
A highly efficient strategy for Cu(OTf)(2) mediated S(N)2-type nucleophilic ring opening followed by [4+2] cycloaddition reactions of enantiopure 2-phenyl-N-tosylazetidines with various aldehydes and ketones afforded a variety of substituted 1,3-oxazinanes and 1,3-amino alcohols in excellent yields, excellent de and good to excellent ee. The proposed S(N)2-type mechanism of the cycloaddition reaction is supported by experimental evidence. (c) 2007 Elsevier Ltd. All rights reserved.
Asymmetric Synthesis of 3-Hydroxyprolines by Photocyclization ofN-(2-Benzoylethyl)glycinamides
amides 1a-c were prepared from the C2-symmetric pyrrolidines 5a-c. Irradiation of these ketones 1a-c gave cis-3-hydroxyprolinamides 10-12 in moderate to good yields (Scheme 3). The de of the photocyclizations depended on the size of the substituents in positions C(2) and C(5) of the chiral pyrrolidine auxiliaries. In addition, the de varied with the reaction temperature, allowing the determination