I2-Mediated Diversity Oriented Diastereoselective Synthesis of Amino Acid Derived trans-2,5-Disubstituted Morpholines, Piperazines, and Thiomorpholines
摘要:
Diastereoselective trans-2,5-disubstituted amino acids derived diverse morpholines, piperazines and thiomorpholines were prepared in 30 min-1 h with high yields through iodine-mediated 6-exotrig type cyclization from a single common synthetic intermediate. The displacement of iodine with hydride ion gave a methyl substituent at the 2-position of morpholines which provides an additional opportunity for diversity oriented nucleophilic substitution on the rings as well as incorporation of substituents at the 5-position from amino acids constituents.
Azabicyclo[3.1.0]hexane-1-ols as frameworks for the asymmetric synthesis of biologically active compounds
作者:Mouhamad Jida、Régis Guillot、Jean Ollivier
DOI:10.1016/j.tetlet.2007.10.003
日期:2007.12
obtained by Ti(IV)-mediated cyclopropanation of amino acid derivatives, constitute versatile, and unprecedented intermediates for the asymmetric synthesis of pharmacologically active products. Indeed, through selective rearrangement, these compounds undergo unusual ring cleavage to lead to pyrrolidinones. Fe(III)-promoted ring opening followed by basic dehydrohalogenation furnishes opticallyactive dihydropyridinones
Cesium Effect: High Chemoselectivity in Direct N-Alkylation of Amines
作者:Ralph Nicholas Salvatore、Advait S. Nagle、Kyung Woon Jung
DOI:10.1021/jo010643c
日期:2002.2.1
A novel method for the mono-N-alkylation of primary amines, diamines, and polyamines was developed using cesium bases in order to prepare secondaryamines efficiently. A cesium base not only promoted alkylation of primary amines but also suppressed overalkylations of the produced secondaryamines. Various amines, alkyl bromides, and alkyl sulfonates were examined, and the results demonstrated this
Convergent and Selective Synthesis of Pyrrolidinones, Piperidinones, Dihydropyridinones and Pyridinols from a Common Intermediate - Potential Precursors of Bioactive Products
作者:Mouhamad Jida、Jean Ollivier
DOI:10.1002/ejoc.200800380
日期:2008.8
furnish racemic pyrrolidinones as a mixture of diastereomers and piperidinones. In contrast, the synthesis of optically active dihydropyridinones was achieved through a one-pot FeCl3/AcONa reaction or performed by using bis(sym-collidine)iodine hexafluorophosphate. Furthermore, whereas the palladium-mediated hydrogenolysis of these dihydropyridinones furnished both chiral piperidinones and original pyridinols
Synthesis of cyclic sulfamoyl carbamates and ureas via ring-closing metathesis
作者:Joseph M. Dougherty、María Jiménez、Paul R. Hanson
DOI:10.1016/j.tet.2005.03.140
日期:2005.6
Synthetic routes to a diverse set of cyclic sulfamoyl carbamates and ureas are reported. These routes utilize 3-component coupling, Mitsunobu alkylation, and ring-closingmetathesis using the second-generation Grubbs catalyst to achieve the synthesis of the target S-heterocyclic compounds. Cyclic S-heterocycles ranging from 9- to 11-membered rings have been obtained.
Efficient Method for the Synthesis of Chiral Pyrrolidine Derivatives via Ring-Closing Enyne Metathesis Reaction
作者:Qian Yang、Howard Alper、Wen-Jing Xiao
DOI:10.1021/ol062959i
日期:2007.3.1
[reaction: see text] A series of new pyrrolidine derivatives were prepared directly in very good yields, from the substrates containing a basic or nucleophilic N atom via ring-closingenynemetathesisreaction under mild reaction conditions. Moreover, the reaction occurs smoothly without the presence of ethylene gas.