Asymmetric Intermolecular Hydroamination of Unactivated Alkenes with Simple Amines
作者:Alexander L. Reznichenko、Hiep N. Nguyen、Kai C. Hultzsch
DOI:10.1002/anie.201004570
日期:2010.11.15
A hard nut to crack: The asymmetric intermolecular Markovnikov addition of simple amines to unactivatedalkenes can be achieved utilizing binaphtholate rare‐earth‐metal catalysts with up to 61 % ee and 73 % de in the case where R2 contains a stereogenic center.
Chiral 1,3-perhydrobenzoxazines 1, 2, and 9-14, prepared by condensation of 8-(benzylamino)menthol with different aldehydes, react with alkylmagnesium bromides and trimethylaluminum leading to the open amino alcohols 3a-d, 4a-d, and 15-20 in excellent chemical yields and good to excellent diastereomeric excess. The sequential elimination of the menthol appendage by heating with P(2)O(5) and the benzyl
One-Pot Asymmetric Synthesis of Either Diastereomer of <i>tert</i>-Butanesulfinyl-protected Amines from Ketones
作者:Jessica Tanuwidjaja、Hillary M. Peltier、Jonathan A. Ellman
DOI:10.1021/jo0616512
日期:2007.1.1
[GRAPHIC]A one-pot method for the asymmetric synthesis of tert-butanesulfinyl-protected amines is described. Condensation of aryl alkyl and dialkyl ketones with tert-butanesulfinamide followed by in situ reduction with the appropriate reagent provides either diastereomer of the sulfinamide products in good yields and with diastereomeric ratios of up to 99:1.
Histamine H3 and H4 receptor affinity of branched 3-(1H-imidazol-4-yl)propyl N-alkylcarbamates
A series of imidazole-containing (non-)chiral carbamates were tested at human histamine H-3 receptor (H3R). All compounds displayed K-i values below 100 nM. A trend for a stereoselectivity at human H3R was observed for the chiral alpha-branched ligands. Selected compounds were also tested at human histamine H-4 receptor and showed moderate to weak affinities (118-1460 nM). (C) 2009 Elsevier Ltd. All rights reserved.
RESOLUTION OF CHIRAL ALIPHATIC AND ARYLALKYL AMINES USING IMMOBILIZED<i>CANDIDA ANTARCTICA</i>LIPASE AND ISOLATION OF THEIR R- AND S-ENANTIOMERS
作者:Bruce A. Davis、David A. Durden
DOI:10.1081/scc-100000584
日期:2001.1
The resolution of chiral aliphatic and arylalkyl amines in high enantiomeric excess (up to 97.5% ee for the R-enantiomers and up to 99.9% ee for the S-enantiomers) and good yield (50-80%) using immobilized Candida antarctica lipase and ethyl acetate as acyl donor has been demonstrated. A second resolution on the R-amine increased the enantiomeric excess to more than 99.5% (up to 99.9%).