Pictet–Spengler reaction based on in situ generated α-amino iminium ions through the Heyns rearrangement

2020 ◽  
Vol 7 (20) ◽  
pp. 3242-3246
Author(s):  
Jun-xiu Liang ◽  
Guo-bin Yang ◽  
Yong-po Zhang ◽  
Dong-dong Guo ◽  
Jin-zhong Zhao ◽  
...  
Keyword(s):  
High Yield ◽  
Tandem Reaction ◽  
Iminium Ions

A useful tandem reaction via the Heyns rearrangement and Pictet–Spengler reaction was developed which ensured the synthesis of complex N-heteropolycycles containing tetrahydro-β-carboline with high yield (up to 96%) and dr (99 : 1).

Catalytic enantioselective synthesis of indolizino[8,7-b]indole alkaloid derivatives based on the tandem reaction of tertiary enamides

2021 ◽  
Author(s):  
Xin-Ming Xu ◽  
Ming Xie ◽  
Jiazhu Li ◽  
Mei-Xiang Wang
Keyword(s):  
Indole Alkaloid ◽  
Enantioselective Synthesis ◽  
High Yield ◽  
Tandem Reaction ◽  
Indole Derivatives

An exquisite Pybox/Cu(OTf)2-catalyzed asymmetric tandem reaction of tertiary enamides was developed, which enabled the expeditious synthesis of indolizino[8,7-b]indole derivatives in high yield, excellent enantioselectivity and diastereoselectivity.

Facile synthesis of indene and fluorene derivatives through AlCl3 -catalyzed cyclization of in situ formed iminium ions

2017 ◽  
Vol 31 (12) ◽  
pp. e3863 ◽  
Author(s):  
Lei Chen ◽  
Wei Teng ◽  
Xin-Le Geng ◽  
Yi-Fan Zhu ◽  
Yong-Hong Guan ◽  
...  
Keyword(s):  
Facile Synthesis ◽  
Iminium Ions

scholarly journals HIGH-YIELD PREPARATION OF ISOLATED RAT LIVER PARENCHYMAL CELLS

1969 ◽  
Vol 43 (3) ◽  
pp. 506-520 ◽  
Author(s):  
M. N. Berry ◽  
D. S. Friend
Keyword(s):  
Gap Junctions ◽  
Rat Liver ◽  
Structural Integrity ◽  
Cell Injury ◽  
High Yield ◽  
Isolated Cells ◽  
Nylon Mesh ◽  
Parenchymal Cells

A new technique employing continuous recirculating perfusion of the rat liver in situ, shaking of the liver in buffer in vitro, and filtration of the tissue through nylon mesh, results in the conversion of about 50% of the liver into intact, isolated parenchymal cells. The perfusion media consist of: (a) calcium-free Hanks' solution containing 0.05% collagenase and 0.10% hyaluronidase, and (b) magnesium and calcium-free Hanks' solution containing 2 mM ethylenediaminetetraacetate. Biochemical and morphologic studies indicate that the isolated cells are viable. They respire in a medium containing calcium ions, synthesize glucose from lactate, are impermeable to inulin, do not stain with trypan blue, and retain their structural integrity. Electron microscopy of biopsies taken during and after perfusion reveals that desmosomes are quickly cleaved. Hemidesmosome-containing areas of the cell membrane invaginate and appear to pinch off and migrate centrally. Tight and gap junctions, however, persist on the intact, isolated cells, retaining small segments of cytoplasm from formerly apposing parenchymal cells. Cells which do not retain tight and gap junctions display swelling of Golgi vacuoles and vacuoles in the peripheral cytoplasm. Cytoplasmic vacuolization in a small percentage of cells and potassium loss are the only indications of cell injury detected. By other parameters measured, the isolated cells are comparable to normal hepatic parenchymal cells in situ in appearance and function.

1-Carba-arachno-pentaborane(10) Derivatives

1997 ◽  
Vol 62 (8) ◽  
pp. 1254-1262 ◽  
Author(s):  
Bernd Wrackmeyer ◽  
Hans-Jörg Schanz
Keyword(s):  
High Yield ◽  
Exchange Reactions ◽  
Nmr Data ◽  
Substituted 1 ◽  
C Nmr

The formation of organo substituted 1-carba-arachno-pentaborane(10) derivatives is shown to proceed in high yield via in situ generated 1,1,1-tris(diethylboryl)propane (2) from diethyl(propyn-1-yl)borane (1) by hydroboration with an excess of diethylborane (hydride bath). In the hydride bath, exchange reactions between 2 and other geminal bis(diethylboryl)alkanes take place until the carbaborane skeleton is formed. If tris(diethylboryl)methane is used under the same conditions, the corresponding 1-carba-arachno-pentaborane(10) derivatives 11 and 12 are formed in mixture with other unknown boranes or carboranes. 11B and 13C NMR data are presented to allow for straightforward identification of the 1-carba-arachno-pentaboranes(10).

Application of Epoxy Resin for Improvement of the Banana Stem-Acoustic Panel

2021 ◽  
Vol 15 ◽  
Author(s):  
Mohd Azril Riduan ◽  
Mohd Jumain Jalil ◽  
Intan Suhada Azmi ◽  
Afifudin Habulat ◽  
Danial Nuruddin Azlan Raofuddin ◽  
...  
Keyword(s):  
Oleic Acid ◽  
Kinetic Modelling ◽  
Low Cost ◽  
Cost Effective ◽  
Performic Acid ◽  
High Yield ◽  
Renewable Materials ◽  
Runge Kutta Method ◽  
To Come

Background: Greener epoxidation by using vegetable oil to create an eco-friendly epoxide is being studied because it is a more cost-effective and environmentally friendly commodity that is safer than non-renewable materials. The aim of this research is to come up with low-cost solutions for banana trunk acoustic panels with kinetic modelling of epoxy-based palm oil. Method: In this study, the epoxidation of palm oleic acid was carried out by in situ performic acid to produce epoxidized palm oleic acid. Results: Banana trunk acoustic panel was successfully innovated based on the performance when the epoxy was applied. Lastly, a mathematical model was developed by using the numerical integration of the 4th order Runge-Kutta method, and the results showed that there is a good agreement between the simulation and experimental data, which validates the kinetic model. Conclusion: Overall, the peracid mechanism was effective in producing a high yield of epoxy from palm oleic acid that is useful for the improvement of acoustic panels based on the banana trunk.

scholarly journals New Biochemical Insights to Unravel the Pathogenesis of Alzheimer's Lesions

1991 ◽  
Vol 18 (S3) ◽  
pp. 408-410 ◽  
Author(s):  
Alex E. Roher ◽  
Kenneth C. Palmer ◽  
John Capodilupo ◽  
Arun R. Wakade ◽  
Melvyn J. Ball
Keyword(s):  
Amyloid Plaque ◽  
Extracellular Proteins ◽  
High Yield ◽  
Chemical Fractionation ◽  
Core Proteins ◽  
Β Amyloid ◽  
Neuritic Sprouting

ABSTRACT:Purification of amyloid plaque core proteins (APCP) from Alzheimer's disease brains to complete homogeneity and in high yield permitted its chemical fractionation and characterization of its components. APCP is mainly made of β-amyloid (βA) and an assortment of glycoproteins (accounting for 20%) rich in carbohydrates compatible with N-and O-linked saccharides. When added to tissue culture of sympathetic and sensory neurons APCP and βA inhibited neuritic sprouting, a reversible phenomenon at low doses. Higher concentrations of both substances kill the neurons in culture. APCP is significantly more toxic than βA, suggesting the minor components may play an important role in increasing the toxicity of βA. If the observed toxic effects of APCP in situ are occurring in vivo during the course of AD, then the accumulation of these extracellular proteins could be largely responsible for some of the neuronal death observed in this neuropathology.

In situ electrogeneration of o-benzoquinone and high yield reaction with benzenethiols in a microflow system

2012 ◽  
Vol 48 (22) ◽  
pp. 2806 ◽  
Author(s):  
Tsuneo Kashiwagi ◽  
Fumihiro Amemiya ◽  
Toshio Fuchigami ◽  
Mahito Atobe
Keyword(s):  
High Yield

scholarly journals Microstructure and mechanical properties of slowly cooled Cu47.5Zr47.5Al5

2007 ◽  
Vol 22 (2) ◽  
pp. 326-333 ◽  
Author(s):  
J. Das ◽  
S. Pauly ◽  
C. Duhamel ◽  
B.C. Wei ◽  
J. Eckert
Keyword(s):  
Mechanical Properties ◽  
Fracture Strain ◽  
Volume Fraction ◽  
Spherical Shape ◽  
High Yield ◽  
High Yield Strength ◽  
Scanning Calorimetry ◽  
Arc Melting ◽  
Martensite Matrix

Cu47.5Zr47.5Al5 was prepared by arc melting and solidified in situ by suction casting into 2–5-mm-diameter rods under various cooling rates (200–2000 K/s). The microstructure was investigated along the length of the rods by electron microscopy, differential scanning calorimetry and mechanical properties were investigated under compression. The microstructure of differently prepared specimens consists of macroscopic spherical shape chemically inhomogeneous regions together with a low volume fraction of randomly distributed CuZr B2 phase embedded in a 2–7 nm size clustered “glassy-martensite” matrix. The as-cast specimens show high yield strength (1721 MPa), pronounced work-hardening behavior up to 2116 MPa and large fracture strain up to 12.1–15.1%. The fracture strain decreases with increasing casting diameter. The presence of chemical inhomogenities and nanoscale “glassy-martensite” features are beneficial for improving the inherent ductility of the metallic glass.

scholarly journals Agro morphological characterization of cashew trees (Anacardium occidental L.), in improvement for the high yield and high quality of raw nuts in Burkina Faso

2021 ◽  
Vol 14 (9) ◽  
pp. 3188-3199
Author(s):  
Windpouiré Vianney Tarpaga ◽  
Larbouga Bourgou ◽  
Moussa Guira ◽  
Albert Rouamba
Keyword(s):  
Burkina Faso ◽  
Core Collection ◽  
Morphological Diversity ◽  
Morphological Characterization ◽  
High Yield ◽  
Morphological Description ◽  
Average Weight ◽  
In Situ Collection

The cashew sector has taken a great economic interest, due to the strong global demand for raw nuts. However, in Burkina Faso, the productivity of orchards still remains low, a consequence of a lack of breeding program on the species. In order to increase yields and improve the quality of the raw nut, efficient clones must be developed. Surveys were carried out and a primary in situ collection was made from which a core collection of 15 trees was extracted. An agro-morphological description of the selected trees and an analysis of the structuration of the variability within them were carried out. The study revealed appreciable agro-morphological diversity through shape, size and color of apple, type of inflorescence, fruiting period and the health of trees. A structure of diversity based on agronomic criteria led to identify 5 groups of trees, characterized by an average weight of the nut between 6.64 and 8.32 g, a kernel rate between 28.10 and 31.26% and a yield per tree between 34.27 and 104.42 kg. Performing trees will be erected as heads of clones for the production of grafted plants. La filière anacarde a pris un grand intérêt économique, suite à la forte demande mondiale en noix brutes. Cependant, au Burkina Faso, la productivité des vergers demeure encore faible, conséquence d’une absence de sélection variétale du matériel végétal. En vue d’accroître les rendements et d’améliorer la qualité de la noix brute, une recherche de clones performants était indispensable. Des prospections ont été conduites et une collection primaire in situ a été constituée dont une core collection de 15 arbres a été extraite. Une description agro-morphologique des arbres sélectionnés et une analyse de la structuration de la variabilité en son sein ont été conduites. L’étude a révélé une diversité agro morphologique appréciable à travers la forme, le calibre et la couleur de la pomme, le type d’inflorescence, la période de fructification et l’état sanitaire des arbres. Une structuration de la diversité basée sur les critères agronomiques a permis d’identifier 5 groupes d’arbres, caractérisés par un poids moyen de la noix compris entre 6,64 et 8,32 g, un taux d’amande compris entre 28,10 et 31,26% et un rendement par arbre compris entre 34,27 et 104,42 kg. Les arbres les plus performants constitueront des têtes de clones pour la production de plants par greffage.

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