Organocatalytic enantioselective synthesis of dihydronaphthofurans and dihydrobenzofurans: reaction development and insights into stereoselectivity

Susam, Zeynep Dilşad
Ozcan, Bilge Deniz
Kurtkaya, Enis
Yıldırım, Erol
Tanyeli, Cihangir
Squaramide/cinchona alkaloid-derived bifunctional organocatalysts are in high demand in asymmetric transformations. Bifunctional quinine-derived sterically encumbered squaramide (H-bond donor) organocatalysts were used to catalyze the asymmetric Friedel-Crafts/S(N)2 type domino reaction of (Z)-alpha-bromonitroalkenes and alpha/beta-naphthols and phenol derivatives to generate enantiomerically enriched dihydronaphthofuran (DHN) and dihydrobenzofuran (DHB) derivatives, respectively. The target adducts were obtained in up to >99% ee under mild conditions with a relatively low catalyst loading (5 mol%) compared to the methods known in the literature. In addition, density functional theory (DFT) calculations were performed to establish a possible outcome, explaining the origin of the stereoselectivity. It was discovered that pi-stacked interactions for the trans-conformation in the Friedel-Crafts step are 0.79 kcal mol(-1) more stable than the cis-conformation.


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A new rate independent porous plasticity model is proposed for the modeling of ductile damage initiation due to void growth in metallic materials. The model is based on a simple yield description which includes two porosity functions that affect both deviatoric and hydrostatic stress evolution. The current version of the model predicts damage solely due to void growth and it should be extended to include the void initiation and coalescence criteria. The numerical examples study the performance of the develo...
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Embedded Si nanocrystals in SiO2 have a large current interest due to the prospects for practical applications. For most of these it is essential to characterize and ultimately control the nanocrystal size, size distribution and spatial distribution. Here we present a study of Si nanocrystals and clusters in SiO2 studied by atomic force microscopy (AFM). Since it is an indirect method, it requires several other methods to establish a reliable description of the structure of the samples. We here compare the ...
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AM1 (unrestricted Hartree-Fock) type semiempirical calculations have been carried out on (Li + nH(2))@C-60 systems having n=0-5. The results predict that these composite structures should be endothermic but stable systems. The Li atom interacts with pi-skeleton of the C-60 structure. The hydrogens inserted into Li@C-60 cage also undergo some interaction. (C) 2002 International Association for Hydrogen Energy. Published by Elsevier Science Ltd. All rights reserved.
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Karul, C; Soyupak, S; Yurteri, C (Springer Science and Business Media LLC, 1999-01-01)
A research was made on the potential use of neural network based models in eutrophication modelling. As a result, an algorithm was developed to handle the practical aspects of designing, implementing and assessing the results of a neural network based model as a lake management tool. To illustrate the advantages and limitations of the neural network model, a case study was carried out to estimate the chlorophyll-a concentration in Keban Dam Reservoir as a function of sampled water quality parameters (PO4 ph...
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Low-complexity beamformer design with practical constraints is an attractive research area for hybrid analog/digital systems in mm-wave massive multiple-input multiple-output (MIMO). This paper investigates interference-aware pre-beamformer (analog beamformer) design for joint spatial division and multiplexing (JSDM) which is a user-grouping based two-stage beamforming method. Single-carrier frequency domain equalization (SC-FDE) is employed in uplink frequency-selective channels. First, unconstrained slowl...
Citation Formats
Z. D. Susam, B. D. Ozcan, E. Kurtkaya, E. Yıldırım, and C. Tanyeli, “Organocatalytic enantioselective synthesis of dihydronaphthofurans and dihydrobenzofurans: reaction development and insights into stereoselectivity,” ORGANIC & BIOMOLECULAR CHEMISTRY, pp. 0–0, 2022, Accessed: 00, 2022. [Online]. Available: