Iron-Catalyzed Alkylation of Carbazole Derivatives via Hydroarylation of Styrenes

2021 ◽  
Author(s):  
En-Kai Xiao ◽  
Xian-Tao Wu ◽  
Feng Ma ◽  
Le-Wei Miu ◽  
Yi-Jun Jiang ◽  
...  
Keyword(s):  
Efficient Method ◽  
Carbazole Derivatives ◽  
Wide Range

The first direct and selective 3,6-di-alkylation of carbazoles via iron-catalyzed hydroarylation of styrenes is demonstrated. This simple, general and efficient method could deliver a wide range of di-benzyl-carbazoles with high...

scholarly journals Prediction of Droplet Production Speed by Measuring the Droplet Spacing Fluctuations in a Flow-Focusing Microdroplet Generator

Micromachines ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 812 ◽  
Author(s):  
Wen Zeng ◽  
Dong Xiang ◽  
Hai Fu
Keyword(s):  
Fluid Flow ◽  
Efficient Method ◽  
Immiscible Fluids ◽  
Droplet Generation ◽  
Flow Focusing ◽  
Flow Conditions ◽  
Flow Rates ◽  
Wide Range ◽  
Droplet Production ◽  
Monodisperse Droplets

In a flow-focusing microdroplet generator, by changing the flow rates of the two immiscible fluids, production speed can be increased from tens to thousands of droplets per second. However, because of the nonlinearity of the flow-focusing microdroplet generator, the production speed of droplets is difficult to quantitatively study for the typical flow-focusing geometry. In this paper, we demonstrate an efficient method that can precisely predict the droplet production speed for a wide range of fluid flow rates. While monodisperse droplets are formed in the flow-focusing microchannel, droplet spacing as a function of time was measured experimentally. We discovered that droplet spacing changes periodically with time during each process of droplet generation. By comparing the frequency of droplet spacing fluctuations with the droplet production speed, precise predictions of droplet production speed can be obtained for different flow conditions in the flow-focusing microdroplet generator.

Repeatable and High-Efficiency Patterning of Silver Nanowires on PDMS Using Micromilled Aluminum Molds

2019 ◽  
Vol 7 (4) ◽  
Author(s):  
Rick Helgason ◽  
Ayan Choudhury ◽  
Yongjun Lai
Keyword(s):  
Efficient Method ◽  
Strain Gauge ◽  
High Efficiency ◽  
Silver Nanowires ◽  
Silver Nanowire ◽  
Two Dimensional ◽  
Wide Range ◽  
Sharp Edges

Abstract We present an inexpensive, repeatable, and efficient method of patterning silver nanowires onto polydimethylsiloxane (PDMS) using a mold-based approach. A micromilling machine is used to prepare an aluminum mold with a raised pattern so that PDMS cured in these molds is imprinted with the design. A solution of silver nanowires and ethanol can then be injected into the pattern. This method can be used to pattern silver nanowires onto PDMS in any two-dimensional (2D) layout, meaning it can be extended to produce a wide range of PDMS/silver nanowire-based sensors and devices. We demonstrate this by the development of two separate patterns. An intricate logo is developed in order to demonstrate the capability of patterning curved and sharp edges, and a strain gauge is developed in order to demonstrate a functional device.

scholarly journals Microwave-assisted urea catalyzed Knoevenagel condensation of aldehydes with active methylene compounds

2020 ◽  
Vol 55 (2) ◽  
pp. 159-164
Author(s):  
WT Purba ◽  
PS Roy ◽  
S Jannat ◽  
SA Begum ◽  
MM Rahman
Keyword(s):  
Microwave Irradiation ◽  
Efficient Method ◽  
Knoevenagel Condensation ◽  
Efficient Catalyst ◽  
Microwave Assisted ◽  
Solvent Free Conditions ◽  
Wide Range ◽  
Active Methylene Compounds ◽  
Reaction Proceeds ◽  
Active Methylene

Rapid and efficient method for the synthesis of substituted olefins such as 2-(4-chlorophenylmethylene) malononitrile, 2-(4-hydroxyphenylmethylene) malononitrile and 2-cyano-3-(4-hydroxyphenyl) acrylamide etc under the influence of microwave irradiation are described. Urea has been utilized as an efficient catalyst for the Knoevenagel condensation of aldehydes with acidic active methylene compounds such as malononitrile, ethylcyanoacetate and cyanoacetamide to afford substituted olefins under the influence of microwave irradiation. The reaction proceeds smoothly under mild and solvent free conditions and the products are obtained in good yield. The method is applicable for a wide range of aldehydes including aromatic and heterocyclic substrates. Bangladesh J. Sci. Ind. Res.55(2), 159-164, 2020

Copper(II)-Promoted Oxidation/[3+2]Cycloaddition/Aromatization Cascade: Efficient Synthesis of Tetrasubstituted NH-Pyrrole from Chalcones and Iminodiacetates

Synlett ◽  
2019 ◽  
Vol 30 (12) ◽  
pp. 1442-1446 ◽  
Author(s):  
Zhang-qi Lin ◽  
Chao-dong Li ◽  
Zi-chun Zhou ◽  
Shuai Xue ◽  
Jian-rong Gao ◽  
...  
Keyword(s):  
Efficient Method ◽  
Cascade Reaction ◽  
Oxidative Cyclization ◽  
Efficient Synthesis ◽  
Reaction Conditions ◽  
Highly Efficient ◽  
Wide Range ◽  
Reaction Proceeds

A simple and highly efficient method for the preparation of tetrasubstituted NH-pyrrole from a wide range of chalcones and diethyl iminodiacetates via a Cu(OAc)2-promoted oxidation/[3+2]cycloaddition/aromatization cascade reaction has been developed. This reaction proceeds through dehydrogenations, deamination, and oxidative cyclization, affording the corresponding products in good to excellent yields. This convenient methodology for constructing tetrasubstituted NH-pyrroles has several advantages over existing methods, such as the use of easily accessible chalcones and readily available diethyl iminodiacetates, and mild reaction conditions. A wide range of substrates are tolerated.

scholarly journals New simple synthesis of ring-fused 4-alkyl-4H-3,1-benzothiazine-2-thiones: Direct formation from carbon disulfide and (E)-3-(2-aminoaryl)acrylates or (E)-3-(2-aminoaryl)acrylonitriles

2013 ◽  
Vol 9 ◽  
pp. 460-466 ◽  
Author(s):  
Qiuping Ding ◽  
Yuqing Lin ◽  
Guangni Ding ◽  
Fumin Liao ◽  
Xiaoyan Sang ◽  
...  
Keyword(s):  
Carbon Disulfide ◽  
Efficient Method ◽  
Simple Synthesis ◽  
Metal Catalyst ◽  
Mild Conditions ◽  
Wide Range ◽  
Direct Formation

A new simple and efficient method to construct ring-fused 4-alkyl-4H-3,1-benzothiazine-2-thione derivatives has been developed from carbon disulfide and (E)-3-(2-aminoaryl)acrylates or (E)-3-(2-aminoaryl)acrylonitriles under mild conditions, without the need for a metal catalyst. The newly developed method tolerates a wide range of substrates in moderate to excellent yields. Moreover, this method is advantageous over previous ones for the easy synthesis of reactants.

Sandwich Beams with Arbitrary Boundary Conditions

1975 ◽  
Vol 97 (3) ◽  
pp. 873-880 ◽  
Author(s):  
Dusan Krajcinovic
Keyword(s):  
Efficient Method ◽  
Present Method ◽  
Sandwich Beams ◽  
Cross Sectional ◽  
Arbitrary Boundary ◽  
Variational Equations ◽  
Material Parameters ◽  
Wide Range ◽  
Derived Set ◽  
Beam Bending

Presented is a practical and efficient method for the analysis of arbitrarily supported sandwich beams. Based on the previously derived set of governing variational equations, the present method utilizes familiar transfer matrix procedure. Final solutions for the displacement and stresses consist of two terms reflecting correspondingly the conventional (solid) beam bending and the cross-sectional distortion. The proposed method is illustrated in a few examples and the results are plotted for a wide range of geometric and material parameters.

Palladium(ii)-mediated rapid 11C-cyanation of (hetero)arylborons

2018 ◽  
Vol 16 (41) ◽  
pp. 7711-7716 ◽  
Author(s):  
Zhouen Zhang ◽  
Takashi Niwa ◽  
Yasuyoshi Watanabe ◽  
Takamitsu Hosoya
Keyword(s):  
Efficient Method ◽  
Pet Tracers ◽  
Highly Efficient ◽  
Wide Range

A highly efficient method applicable to the synthesis of a wide range of [11C]cyanoarenes, including PET tracers for aromatase imaging, has been developed by a palladium(ii)-mediated rapid 11C-cyanation of (hetero)arylborons with [11C]cyanides.

Original disymmetric bolaforms bearing at least one sulfobetaine head; synthesis and surface properties

2001 ◽  
Vol 79 (7) ◽  
pp. 1153-1158 ◽  
Author(s):  
Souad Souirti ◽  
Michel Baboulène
Keyword(s):  
Surface Properties ◽  
Functional Groups ◽  
Efficient Method ◽  
Aqueous Media ◽  
Critical Micellar Concentration ◽  
Excellent Yield ◽  
Wide Range ◽  
Self Aggregation ◽  
Cationic Amphiphile

We describe a simple and efficient method for the synthesis of disymmetric bolaforms bearing at least one sulfobetaine head. In this process, we could introduce successively on α, ω-bis(dialkylamino) alkane a sulfobetaine head and a cationic, a sulfobetaine, or a carboxybetaine head, in excellent yield. This is the first synthesis of disymmetric sulfobetaine bolaforms. The method is easily generalized to various types of head functional groups. The wide range of bolaforms produced by this method has been exploited to study their surface properties and to determine the respective roles of the polar heads and the lengths of the spacers (n) on self-aggregation in aqueous media. A critical micellar concentration (cmc) was observed with the compounds with a spacer of 12 carbon atoms (n = 12). Micellization appeared to be consistent with a "wicket-like" conformation, which did not appear to form with the n = 8 compounds.Key words: disymmetric bolaform, sulfobetaine, carboxybetaine, cationic amphiphile, synthesis, surface properties.

scholarly journals A unified analytical parametric method for kinematic analysis of planar mechanisms

2021 ◽  
pp. 030641902097817
Author(s):  
Kazem Abhary
Keyword(s):  
Efficient Method ◽  
Kinematic Analysis ◽  
Teaching And Learning ◽  
Parametric Method ◽  
Complex Mechanism ◽  
Planar Mechanisms ◽  
Position Analysis ◽  
Wide Range ◽  
Acceleration Analysis

This paper describes a method for unified parametric kinematic analysis of those planar mechanisms whose geometry can be defined with a set of independent vectorial loops, i.e. solvable independently; this covers a wide range of planar mechanisms. The method is developed by employing the well-known vectorial illustration, and vectorial-loop equations solved with the aid of complex polar algebra leading to a total of only nine unified/generic one-unknown parametric equations consisting of five equations for position analysis and two equations for velocity and acceleration analysis each. Then, the kinematics of joints and mass centers are manifested as resultants of a few known vectors. This method is needless of relative-velocities, relative-accelerations, instantaneous centers of rotation and Kennedy’s Theorem dominantly used in the literature, especially textbooks. The efficiency of the method is demonstrated by its application to a complex mechanism through only eight unified equations, and simultaneously compared to the solution using the textbook common (Raven’s) method which required the derivation of 67 extra equations to get the same results. This reveals the fact that the method is not only a powerful tool for mechanical designers but a most powerful and efficient method for teaching and learning the kinematics of planar mechanisms.

scholarly journals Optical Solutions of Fokas-Lenells Equation via (m-1/G') - Expansion Method

2020 ◽  
Vol 7 ◽  
pp. 20-24
Author(s):  
Hasan Bulut ◽  
Khalid ◽  
Ban Jamal
Keyword(s):  
Partial Differential Equations ◽  
Differential Equations ◽  
Exact Solutions ◽  
Efficient Method ◽  
Nonlinear Partial Differential Equations ◽  
Soliton Solutions ◽  
Expansion Method ◽  
Three Dimensions ◽  
Partial Differential ◽  
Wide Range

In this research paper, we investigate some novel soliton solutions to the perturbed Fokas-Lenells equation by using the (m + 1/G') expansion method. Some new solutions are obtained and they are plotted in two and three dimensions. This technique appears as a suitable, applicable, and efficient method to search for the exact solutions of nonlinear partial differential equations in a wide range. All gained optical soliton solutions are substituted into the FokasLenells equation and they verify it. The constraint conditions are also given.

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