Enantioselective aza-Henry reaction of t-boc protected imines and nitroalkanes with bifunctional squaramide organocatalysts

Susam, Dilşad
The first part of this thesis comprises the application of a Cinchona alkaloid derived, bifunctional squaramide organocatalyst in the aza-Henry reaction of t-Boc protected imines and nitroalkanes. The target chiral β-nitroamines are chosen because; they are quite feasible for the corresponding α-amino acids and 1,2-diamines, which are basic structural motif in many natural products and key materials of the many pharmaceuticals. In this part, 12 different chiral β-nitroamine derivatives were synthesized with quinine based novel bifunctional organocatalyst, which has been developed in our group, up to 91% ee under the optimized condition with 10 mol% catalyst loading. In the second part of the thesis, preliminary studies of enantioselective Henry, aldol, decarboxylative aldol and Friedel-Crafts type substitution domino reactions were conducted with bifunctional organocatalysts. Among these studies, the best result was achieved with Friedel-Crafts type substitution domino reaction as 92% ee in 10 minutes.


Immobilization of dioxomolybdenum(VI) complex bearing salicylidene 2-picoloyl hydrazone on chloropropyl functionalized SBA-15: A highly active, selective and reusable catalyst in olefin epoxidation
Bagherzadeh, Mojtaba; Zare, Maryam; Salemnoush, Taghi; Özkar, Saim; Akbayrak, Serdar (Elsevier BV, 2014-04-05)
A novel organic-inorganic hybrid heterogeneous catalyst system was obtained from the reaction of the molybdenum(VI) complex of salicylidene 2-picoloyl hydrazone with mesoporous silica containing 3-chloropropyl groups prepared by a direct synthetic approach involving hydrolysis and co-condensation of tetraethylorthosilicate (TEOS) and 3-chloropropyltrimethoxysilane in the presence of the triblock copolymer P123 as template under acidic conditions. Characterization of the functionalized materials by X-ray dif...
Enantioselective aza-Henry reaction of t-Boc protected imines and nitroalkanes with bifunctional squaramide organocatalysts
Susam, Zeynep Dilşad; Tanyeli, Cihangir (2017-05-07)
An organocatalytic asymmetric aza-Henry reaction of t-Boc protected imines with nitroalkanes has been established by chiral acid-base type bifunctional Cinchona alkaloid/squaramide organocatalysts. The cooperation of a quinine motif as a base and sterically encumbered squaramide (H-bond donor) enabled mostly complete conversion of a range of reactants into the corresponding aza-Henry products at room temperature with good selectivities (up to 91% ee with 10 mol% catalyst loading).
NiMoS/gamma-Al2O3 catalysts: The nature and the aging behavior of active sites in HDN reactions
ZHANG, LEE P; Karakaş, Gürkan; OZKAN, UMIT S (Elsevier BV, 1998-09-10)
The work presented in this paper is a continuation of our earlier work aimed at acquiring a fundamental understanding of sulfided Ni-Mo/gamma-Al2O3 catalysts in HDN catalysis, A series of temperature-programmed desorption and reduction experiments were performed over in-situ sulfided bare gamma-alumina support, alumina-supported monometallic Ni, Mo, and bimetallic NiMo catalysts. The TPD and TPR results were linked to the active site assignment of Ni- and Mo-associated centers in HDN reactions. Postreaction...
Enantioselective synthesis of both enantiomers of 2-amino-2-(2-furyl)ethan-1-ol as a flexible building block for the preparation of serine and azasugars
Demir, Ayhan Sıtkı; Sesenoglu, O; Aksoy-Cam, H; Kaya, H; Aydogan, K (Elsevier BV, 2003-05-16)
The selective conversion of 1-(2-furyl)-2-hydroxyethan-1-one and ethyl 2-(2-furyl)-2-oxo acetate into (E)- and (Z)-oximes and oxime ethers followed by oxazaborolidine-catalyzed enantioselective reduction using different amino alcohols furnished both enantiomers of the important chiral building block 2-amino-2-(2-furyl)ethan-1-ol with an ee of up to 96%.
Vertex‐sharing BO4 and PO4 tetrahedra form the framework of the title compounds. Ca[BPO5] and Sr[BPO5] crystallize in the stillwellite structural type and contain tetrahedral chain anions urn:x-wiley:05700833:media:ANIE199407491:tex2gif-stack-1[BPOurn:x-wiley:05700833:media:ANIE199407491:tex2gif-stack-2], which can be described as loop‐branched “dreier” single chains. In Ba3[BP3O12] the urn:x-wiley:05700833:media:ANIE199407491:tex2gif-stack-3tetrahedral anions form “zweifach” open “vierer” single chains. Gi...
Citation Formats
D. Susam, “Enantioselective aza-Henry reaction of t-boc protected imines and nitroalkanes with bifunctional squaramide organocatalysts,” M.S. - Master of Science, Middle East Technical University, 2015.