Direct Transformation of N-Protected α,β-Unsaturated γ-Amino Amides into γ-Lactams through a Base-Mediated Molecular Rearrangement

2019 ◽  
Vol 84 (23) ◽  
pp. 15145-15153
Author(s):  
Mothukuri Ganesh Kumar ◽  
Kuruva Veeresh ◽  
Sachin A. Nalawade ◽  
Raj V. Nithun ◽  
Hosahudya N. Gopi
Keyword(s):  
Molecular Rearrangement ◽  
Direct Transformation ◽  
Amino Amides

Dielectric Relaxation Studies of Silver Nanoparticles dispersed Liquid Crystal

2015 ◽  
Vol 8 (3) ◽  
pp. 2176-2188 ◽  
Author(s):  
Keisham Nanao Singh
Keyword(s):  
Activation Energy ◽  
Silver Nanoparticles ◽  
Liquid Crystal ◽  
Dielectric Relaxation ◽  
Relaxation Process ◽  
Relaxation Times ◽  
Low Frequency ◽  
Bulk Liquid ◽  
Molecular Rearrangement ◽  
Relaxation Studies

This article reports on the Dielectric Relaxation Studies of two Liquid Crystalline compounds - 7O.4 and 7O.6 - doped with dodecanethiol capped Silver Nanoparticles. The liquid crystal molecules are aligned homeotropically using CTAB. The low frequency relaxation process occurring above 1 MHz is fitted to Cole-Cole formula using the software Dielectric Spectra fit. The effect of the Silver Nanoparticles on the molecular dipole dynamics are discussed in terms of the fitted relaxation times, Cole-Cole distribution parameter and activation energy. The study indicate a local molecular rearrangement of the liquid crystal molecules without affecting the order of the bulk liquid crystal molecules but these local molecules surrounding the Silver Nanoparticles do not contribute to the relaxation process in the studied frequency range. The observed effect on activation energy suggests a change in interaction between the nanoparticles/liquid crystal molecules.

Total Synthesis of (+)-Granatumine A and Related Bislactone Limonoid Alkaloids via a Pyran to Pyridine Interconversion

2019 ◽  
Author(s):  
Timothy Newhouse ◽  
Alexander Schuppe ◽  
Yizhou Zhao ◽  
Yannan Liu
Keyword(s):  
Total Synthesis ◽  
Inhibitory Activity ◽  
Knoevenagel Condensation ◽  
Cost Effective ◽  
Effective Procedure ◽  
Direct Transformation ◽  
Structural Revision ◽  
Alpha Beta ◽  
Ptp 1B

We report the first total synthesis of (+)-granatumine A, a limonoid alkaloid with PTP-1B inhibitory activity, in 10 steps. Over the course of this study, two key methodological advances were made: a cost effective procedure for ketone alpha,beta-dehydrogenation using allyl-Pd catalysis, and a Pd-catalyzed protocol to convert epoxyketones to 1,3-diketones. The central tetrasubstituted pyridine is formed by a convergent Knoevenagel condensation and carbonyl-selective electrocyclization cascade, which was followed by a direct transformation of a 2<i>H</i>-pyran to a pyridine. These studies have led to the structural revision of two members of this family.

Cyclization Dichotomy of D-xylo-Hex-5-ulosonamides and Synthesis of Piperidine Analogs of Aldohexoses and Aldohexono-1,5-lactones

1999 ◽  
Vol 64 (4) ◽  
pp. 673-684 ◽  
Author(s):  
Radka Kováříková ◽  
Miroslav Ledvina ◽  
David Šaman
Keyword(s):  
Boat Conformation ◽  
Direct Transformation

The preparation of 2,3,4,6-tetra-O-benzyl-5-D-xylo-hex-5-ulosonamides 3a and 3b and their cyclization to 5-amino-2,3,4,6-tetra-O-benzyl-5-deoxy-D-glucono-1,5-lactam (4) and 5-amino- 2,3,4,6-tetra-O-benzyl-5-deoxy-D-talono-1,5-lactam (5) or to 2,3,4,6-tetra-O-benzyl-1,5-dideoxy-1,5-imino-D-glucitol (9), and also their direct transformation into 2,3,4,6-tetra-O-benzyl- D-talono-1,5-lactone (6), are described and discussed. The atypical boat conformation of D-talonolactam 5 and D-talonolactone 6 was found.

Transition-metal-free and facile synthesis of 3-alkynylpyrrole-2, 4-dicarboxylates from methylene isocyanides and propiolaldehyde

2021 ◽  
Author(s):  
Xiaoli Huo ◽  
Xiaojuan Chen ◽  
Liya Yu ◽  
Chong Zhang ◽  
Linghui Zeng ◽  
...  
Keyword(s):  
Transition Metal ◽  
Efficient Method ◽  
Transformation Process ◽  
Facile Synthesis ◽  
Direct Transformation ◽  
Metal Free

A transition-metal-free, facile and efficient method for the synthesis of 3-alkynylpyrrole-2, 4-dicarboxylates from methylene isocyanides and propiolaldehyde with moderate to good yields has been developed. The direct transformation process and...

Synthesis of unsymmetrical phenylurea derivatives via oxidative cross coupling of aryl formamides with amines under metal-free conditions

2015 ◽  
Vol 39 (2) ◽  
pp. 805-809 ◽  
Author(s):  
Nagireddy Veera Reddy ◽  
Pailla Santhosh Kumar ◽  
Peddi Sudhir Reddy ◽  
Mannepalli Lakshmi Kantam ◽  
Kallu Rajender Reddy
Keyword(s):  
Cross Coupling ◽  
Hypervalent Iodine ◽  
Direct Transformation ◽  
Metal Free

A direct transformation of N-aryl formamides to the corresponding phenylurea derivatives via the formation of isocyanate intermediates is achieved in good yields using hypervalent iodine reagents as external oxidants.

scholarly journals Molecular rearrangement of waxy and normal maize starch granules during in vitro digestion

2016 ◽  
Vol 139 ◽  
pp. 10-19 ◽  
Author(s):  
Anju Teng ◽  
Torsten Witt ◽  
Kai Wang ◽  
Ming Li ◽  
Jovin Hasjim
Keyword(s):  
In Vitro Digestion ◽  
Starch Granules ◽  
Maize Starch ◽  
Molecular Rearrangement ◽  
Normal Maize

The Effects of pH on the Supramolecular Structure of Amino Amides

2021 ◽  
Vol 6 (14) ◽  
pp. 3339-3346
Author(s):  
Eltonh Islas‐Trejo ◽  
Concepción Avila‐Montiel ◽  
Hugo Tlahuext ◽  
Víctor D. Lechuga‐Islas ◽  
Antonio R. Tapia‐Benavides ◽  
...  
Keyword(s):  
Supramolecular Structure ◽  
Effects Of Ph ◽  
Amino Amides
Sign in / Sign up

Export Citation Format

Share Document