scholarly journals A Novel, One-Step Palladium and Phenylsilane Activated Amidation from Allyl Ester on Solid Support

2008 ◽  
Vol 2008 ◽  
pp. 1-4
Author(s):  
Zheming Ruan ◽  
Katy Van Kirk ◽  
Christopher B. Cooper ◽  
R. Michael Lawrence
Keyword(s):  
Carboxylic Acid ◽  
Solid Phase ◽  
Direct Conversion ◽  
Solid Support ◽  
Phase Array ◽  
Reaction Conditions ◽  
Allyl Ester ◽  
One Step ◽  
Allyl Esters

The direct conversion of solid-supported carboxylic acid allyl esters to carboxamides through the use of phenylsilane and catalytic Pd under mild reaction conditions is reported. The use of this methodology for the generation of a 48 compound solid-phase array is described herein.

Ketones from Nickel-Catalyzed Decarboxylative, Non-Symmetric Cross-Electrophile Coupling of Carboxylic Acid Esters

2019 ◽  
Author(s):  
Jiang Wang ◽  
Brian P. Cary ◽  
Peyton Beyer ◽  
Samuel H. Gellman ◽  
Daniel Weix
Keyword(s):  
Carboxylic Acid ◽  
Solid Support ◽  
Reaction Conditions ◽  
Decarboxylative Coupling ◽  
New Strategy ◽  
The Cross ◽  
Acyl Donors ◽  
Acid Esters

A new strategy for the synthesis of ketones is presented based upon the decarboxylative coupling of N-hydroxyphthalimide (NHP) esters with S-2-pyridyl thioesters. The reactions are selective for the cross-coupled product because NHP esters act as radical donors and the thioesters act as acyl donors. The reaction conditions are general and mild, with over 40 examples presented, including larger fragments and the 20-mer peptide Exendin(9-39) on solid support.

Facile one-step solid-phase synthesis of multitopic organic–DNA hybrids via “click” chemistry

2014 ◽  
Vol 5 (3) ◽  
pp. 1091-1096 ◽  
Author(s):  
Ryan V. Thaner ◽  
Ibrahim Eryazici ◽  
Omar K. Farha ◽  
Chad A. Mirkin ◽  
SonBinh T. Nguyen
Keyword(s):  
Click Chemistry ◽  
Small Molecule ◽  
Solid Phase Synthesis ◽  
Solid Phase ◽  
Solid Support ◽  
One Pot ◽  
Phase Synthesis ◽  
One Step

Small molecule–DNA hybrids can be synthesized in a one-pot fashion and in good yields by coupling multiazide cores to alkyne-modified DNAs on a solid support using click chemistry.

Ketones from Nickel-Catalyzed Decarboxylative, Non-Symmetric Cross-Electrophile Coupling of Carboxylic Acid Esters

2019 ◽  
Author(s):  
Jiang Wang ◽  
Brian P. Cary ◽  
Peyton Beyer ◽  
Samuel H. Gellman ◽  
Daniel Weix
Keyword(s):  
Carboxylic Acid ◽  
Solid Support ◽  
Reaction Conditions ◽  
Decarboxylative Coupling ◽  
New Strategy ◽  
The Cross ◽  
Acyl Donors ◽  
Acid Esters

A new strategy for the synthesis of ketones is presented based upon the decarboxylative coupling of N-hydroxyphthalimide (NHP) esters with S-2-pyridyl thioesters. The reactions are selective for the cross-coupled product because NHP esters act as radical donors and the thioesters act as acyl donors. The reaction conditions are general and mild, with over 40 examples presented, including larger fragments and the 20-mer peptide Exendin(9-39) on solid support.

Direct Cyclization of Alkenyl Thioester via Transition Metal‐hydrogen Atom Transfer/radical‐polar Crossover Mechanism

2019 ◽  
Author(s):  
Shiori Date ◽  
Kensei Hamasaki ◽  
Karen Sunagawa ◽  
Hiroki Koyama ◽  
Chikayoshi Sebe ◽  
...  
Keyword(s):  
Natural Products ◽  
Hydrogen Atom ◽  
Transition Metal ◽  
Hydrogen Atom Transfer ◽  
Synthetic Method ◽  
Atom Transfer ◽  
Reaction Conditions ◽  
Hydride Hydrogen ◽  
Sulfur Heterocycles ◽  
One Step

<div>We report here a catalytic, Markovnikov selective, and scalable synthetic method for the synthesis of saturated sulfur heterocycles, which are found in the structures of pharmaceuticals and natural products, in one step from an alkenyl thioester. Unlike a potentially labile alkenyl thiol, an alkenyl thioester is stable and easy to prepare. The powerful Co catalysis via a cobalt hydride hydrogen atom transfer and radical-polar crossover mechanism enabled simultaneous cyclization and deprotection. The substrate scope was expanded by the extensive optimization of the reaction conditions and tuning of the thioester unit.</div>

Fully Automated Parallel Oligonucleotide Synthesizer

2001 ◽  
Vol 66 (8) ◽  
pp. 1299-1314 ◽  
Author(s):  
Michal Lebl ◽  
Christine Burger ◽  
Brett Ellman ◽  
David Heiner ◽  
Georges Ibrahim ◽  
...  
Keyword(s):  
Solid Phase ◽  
Building Blocks ◽  
Solid Support ◽  
Continuous Operation ◽  
Gear Pump ◽  
Oligonucleotide Synthesis ◽  
Center Of Rotation ◽  
Microtiter Plates ◽  
The Individual ◽  
Design And Construction

Design and construction of automated synthesizers using the tilted plate centrifugation technology is described. Wash solutions and reagents common to all synthesized species are delivered automatically through a 96-channel distributor connected to a gear pump through two four-port selector valves. Building blocks and other specific reagents are delivered automatically through banks of solenoid valves, positioned over the individual wells of the microtiterplate. These instruments have the following capabilities: Parallel solid-phase oligonucleotide synthesis in the wells of polypropylene microtiter plates, which are slightly tilted down towards the center of rotation, thus generating a pocket in each well, in which the solid support is collected during centrifugation, while the liquid is expelled from the wells. Eight microtiterplates are processed simultaneously, providing thus a synthesizer with a capacity of 768 parallel syntheses. The instruments are capable of unattended continuous operation, providing thus a capacity of over two millions 20-mer oligonucleotides in a year.

scholarly journals Influence of Cu on the Improvement of Magnetic Properties and Structure of L10 FePt Nanoparticles

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1097
Author(s):  
Luran Zhang ◽  
Xinchen Du ◽  
Hongjie Lu ◽  
Dandan Gao ◽  
Huan Liu ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Annealing Temperature ◽  
Reduction Method ◽  
Solid Phase ◽  
Average Particle Size ◽  
Fept Nanoparticles ◽  
Average Particle ◽  
Phase Reduction ◽  
Different Temperatures ◽  
One Step

L10 ordered FePt and FePtCu nanoparticles (NPs) with a good dispersion were successfully fabricated by a simple, green, one-step solid-phase reduction method. Fe (acac)3, Pt (acac)2, and CuO as the precursors were dispersed in NaCl and annealed at different temperatures with an H2-containing atmosphere. As the annealing temperature increased, the chemical order parameter (S), average particle size (D), coercivity (Hc), and saturation magnetization (Ms) of FePt and FePtCu NPs increased and the size distribution range of the particles became wider. The ordered degree, D, Hc, and Ms of FePt NPs were greatly improved by adding 5% Cu. The highest S, D, Hc, and Ms were obtained when FePtCu NPs annealed at 750 °C, which were 0.91, 4.87 nm, 12,200 Oe, and 23.38 emu/g, respectively. The structure and magnetic properties of FePt and FePtCu NPs at different annealing temperatures were investigated and the formation mechanism of FePt and FePtCu NPs were discussed in detail.

scholarly journals Reaction Mechanism for Methane-to-Methanol in Cu-SSZ-13: First-Principles Study of the Z2[Cu2O] and Z2[Cu2OH] Motifs

Catalysts ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 17
Author(s):  
Unni Engedahl ◽  
Adam A. Arvidsson ◽  
Henrik Grönbeck ◽  
Anders Hellman
Keyword(s):  
Liquid Fuel ◽  
Density Functional ◽  
Reaction Pathway ◽  
Direct Conversion ◽  
Reaction Conditions ◽  
Oxidation Of Methane ◽  
Small Pore ◽  
Desorption Step ◽  
Solution Gas ◽  
Stable Motif

As transportation continues to increase world-wide, there is a need for more efficient utilization of fossil fuel. One possibility is direct conversion of the solution gas bi-product CH4 into an energy-rich, easily usable liquid fuel such as CH3OH. However, new catalytic materials to facilitate the methane-to-methanol reaction are needed. Using density functional calculations, the partial oxidation of methane is investigated over the small-pore copper-exchanged zeolite SSZ-13. The reaction pathway is identified and the energy landscape elucidated over the proposed motifs Z2[Cu2O] and Z2[Cu2OH]. It is shown that the Z2[Cu2O] motif has an exergonic reaction path, provided water is added as a solvent for the desorption step. However, a micro-kinetic model shows that neither Z2[Cu2O] nor Z2[Cu2OH] has any notable activity under the reaction conditions. These findings highlight the importance of the detailed structure of the active site and that the most stable motif is not necessarily the most active.

TBAI Catalyzed Electrochemical C-H Bond Activation of 2-arylated-N-methoxyamides for the Synthesis of Phenanthridinones

Synlett ◽  
2021 ◽  
Author(s):  
Kripa Subramanian ◽  
Subhash L. Yedage ◽  
Kashish Sethi ◽  
Bhalchandra M. Bhanage
Keyword(s):  
Electrochemical Method ◽  
Bond Activation ◽  
Supporting Electrolyte ◽  
Bioactive Compound ◽  
Reaction Conditions ◽  
Redox Catalyst ◽  
Synthetic Utility ◽  
One Step ◽  
Constant Potential

An electrochemical method for the synthesis of phenanthridinones via constant potential electrolysis (CPE) mediated by <i>n</i>-Bu<sub>4</sub>NI (TBAI) has been reported. The protocol is metal and oxidant free and proceeds with 100% current efficiency. Here TBAI plays the dual role of the redox catalyst as well as supporting electrolyte. The intramolecular C-H activation proceeds under mild reaction conditions and short reaction time via electrochemically generated amidyl radicals. The reaction has been scaled up to gram level showing its practicability and the synthetic utility and applicability of the protocol has been demonstrated by the direct one-step synthesis of the bioactive compound Phenaglaydon.

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