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Thioamides, Quinolinium and Isoquinolinium Salts: Useful Synthons in the Synthesis of Heterocyclic Compounds and Asymmetric Synthesis of Sulfonic acid Derivatives
, Ph.D. Dissertation Sharif University of Technology ; Matloubi Moghaddam, Firouz (Supervisor)
Abstract
We have reported a new and efficient synthesis of a broad spectrum of heterotetracyclic benzoxazocines via unique tandem 1,3-dinucleophilic addition of different bifunctional nucleophiles to quinolinium and isoquinolinium salts. The reaction generally involves the initial addition of nucleophiles to quinolinium salts to form enamine intermediate which can be trapped by intramolecular O/S-alkylation of nucleophiles. This protocol is a very mild and simple method for construction of eight-membered ring in fused heterocycles in a one-step process. We have also developed an efficient asymmetric synthesis of α,β-disubstituted γ-bisalkoxycarbonyl and α, β- disubstituted γ- phosphono sulfonates via...
Efficient diastereo- and enantioselective synthesis of α,β-disubstituted γ-phosphono sulfonates
, Article Tetrahedron Asymmetry ; Volume 20, Issue 21 , 2009 , Pages 2429-2431 ; 09574166 (ISSN) ; Mirjafary, Z ; Saeidian, H
2009
Abstract
The first asymmetric synthesis of α,β-disubstituted γ-phosphono sulfonates is reported. The key step is the Michael addition of a lithiated enantiopure sulfonate bearing an inexpensive chiral sugar auxiliary to α,β-unsaturated phosphonates in good diastereoselectivities. After chromatographic purification, the cleavage of the chiral sugar auxiliary proceeds without any epimerization or racemization to form the corresponding isopropyl sulfonate in very good overall yield (75%) and excellent diastereomeric and enantiomeric excess (de, ee ≥ 95%). © 2009 Elsevier Ltd. All rights reserved
Organocatalytic synthesis of chiral benzopyrans
, Article Tetrahedron Asymmetry ; Volume 17, Issue 12 , 2006 , Pages 1763-1767 ; 09574166 (ISSN) ; Hojabri, L ; Matloubi Moghaddam, F ; Arvidsson, P. I ; Sharif University of Technology
2006
Abstract
Benzopyrans, or chromenes, are widespread in nature and are considered to be a privileged scaffold in medicinal chemistry. Herein, we report the first organocatalyzed asymmetric synthesis of chiral benzopyrans. The benzopyran unit is constructed through a domino reaction involving an oxa-Michael attack of salicylic aldehyde derivatives onto α,β-unsaturated aldehydes, activated through iminium-ion formation with the organocatalyst, followed by an intramolecular aldol reaction and subsequent elimination of water. This overall reaction sequence provides benzopyrans with aromatic C-2 substituents in up to 60% yield and 60% enantioselectivity, while C-2 aliphatic analogues can be obtained in 90%...
Tailoring dicobalt pacman complexes of schiff-base calixpyrroles towards dioxygen reduction catalysis
, Article Chemical Communications ; Volume 46, Issue 5 , 2010 , Pages 710-712 ; 13597345 (ISSN) ; Bani Yaghoob, S ; Boghaei, D. M ; Slawin, A. M. Z ; Love, J. B ; Sharif University of Technology
2010
Abstract
By modifying the mouth of a macrocyclic dicobalt Pacman complex, it is possible to both isolate new bridging-superoxo and hydroxyl complexes and to tune the reactivity of this system towards catalytic four-electron reduction of dioxygen to water
Diastereo- and enantioselective synthesis of α,β-disubstituted γ-nisalkoxycarbonyl sulfonates
, Article Synlett ; Issue 17 , 2009 , Pages 2872-2874 ; 09365214 (ISSN) ; Saeidian, H ; Mirjafary, Z ; Iffland, D ; Raabe, G ; Runsink, J ; Sharif University of Technology
2009
Abstract
The asymmetric synthesis of ,-disubstituted -bisalkoxycarbonyl sulfonates is reported. The synthesis is based on the Michael addition of a lithiated enantiopure sulfonate bearing a cheap chiral sugar auxiliary to Knoevenagel acceptors. The reaction proceeds with high asymmetric inductions (ds=69-96%) and good yields (62-79%). The absolute configuration was determined by X-ray crystal-structure analysis