scholarly journals Expedient Method for Direct Mono-amidation of Phosphonic and Phosphoric Acids

2020 ◽  
Author(s):  
Victoria Yan ◽  
Cong-Dat Pham ◽  
Florian Muller
Keyword(s):  
State Of The Art ◽  
Triphenylphosphine Oxide ◽  
Water Extraction ◽  
Nucleotide Analogues ◽  
Redox Pair ◽  
Benzylic Amines ◽  
Synthetic Approaches ◽  
Phosphoric Acids

Mono-amidated P(V) pro-drugs predominately contribute to the vastly improved delivery of phosphate and phosphonate-containing anti-viral/cancer nucleotide analogues. However, synthetic approaches towards their formation are often harsh and unreliable, which may hamper the identification of novel, more effective amine pro-drugs. Here, we show that direct mono-amidation of structurally complex phosphonic and phosphoric acids may be accomplished in as quickly as seconds by re-purposing the PPh<sub>3</sub>/DIAD redox pair. Where the triphenylphosphine oxide byproduct is often cited as a vulnerability, we use its formation as an asset. Juxtaposing the anionic nature of the generated mono-amidated product, the desired product may be isolated with a single water extraction. Compared to state-of-the-art strategies towards phosphoramidates, our approach is mild, reliable, and enables access to a variety of aliphatic and benzylic amines for pro-drug attachment.

scholarly journals Expedient Method for Direct Mono-amidation of Phosphonic and Phosphoric Acids

2020 ◽  
Author(s):  
Victoria Yan ◽  
Cong-Dat Pham ◽  
Florian Muller
Keyword(s):  
State Of The Art ◽  
Triphenylphosphine Oxide ◽  
Water Extraction ◽  
Nucleotide Analogues ◽  
Redox Pair ◽  
Benzylic Amines ◽  
Synthetic Approaches ◽  
Phosphoric Acids

Mono-amidated P(V) pro-drugs predominately contribute to the vastly improved delivery of phosphate and phosphonate-containing anti-viral/cancer nucleotide analogues. However, synthetic approaches towards their formation are often harsh and unreliable, which may hamper the identification of novel, more effective amine pro-drugs. Here, we show that direct mono-amidation of structurally complex phosphonic and phosphoric acids may be accomplished in as quickly as seconds by re-purposing the PPh<sub>3</sub>/DIAD redox pair. Where the triphenylphosphine oxide byproduct is often cited as a vulnerability, we use its formation as an asset. Juxtaposing the anionic nature of the generated mono-amidated product, the desired product may be isolated with a single water extraction. Compared to state-of-the-art strategies towards phosphoramidates, our approach is mild, reliable, and enables access to a variety of aliphatic and benzylic amines for pro-drug attachment.

scholarly journals Mixed Polymer Brushes for “Smart” Surfaces

Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1553 ◽  
Author(s):  
Mingxiao Li ◽  
Christian W. Pester
Keyword(s):  
Phase Behavior ◽  
Experimental Work ◽  
Smart Materials ◽  
Polymer Brushes ◽  
State Of The Art ◽  
Future Studies ◽  
Smart Surfaces ◽  
Synthetic Approaches ◽  
Novel Applications ◽  
External Stimuli

Mixed polymer brushes (MPBs) are composed of two or more disparate polymers covalently tethered to a substrate. The resulting phase segregated morphologies have been extensively studied as responsive “smart” materials, as they can be reversible tuned and switched by external stimuli. Both computational and experimental work has attempted to establish an understanding of the resulting nanostructures that vary as a function of many factors. This contribution highlights state-of-the-art MPBs studies, covering synthetic approaches, phase behavior, responsiveness to external stimuli as well as novel applications of MPBs. Current limitations are recognized and possible directions for future studies are identified.

scholarly journals DMF as CO Surrogate in Carbonylation Reactions: Principles and Application to the Synthesis of Heterocycles

Catalysts ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1531
Author(s):  
Biswajit Panda ◽  
Gianluigi Albano
Keyword(s):  
Carbon Monoxide ◽  
Transition Metal ◽  
State Of The Art ◽  
Low Cost ◽  
Environmentally Friendly ◽  
Synthetic Method ◽  
General State ◽  
Future Directions ◽  
Metal Catalyzed ◽  
Synthetic Approaches

Transition metal-catalyzed carbonylation reactions have emerged as one of the most relevant synthetic approaches for the preparation of carbonyl-containing molecules. The most commonly used protocol for the insertion of a carbonyl moiety is the use of carbon monoxide (CO) but, due to its toxic and explosive nature, this process is not suitable at an industrial scale. More recently, the chemistry of CO surrogates has received large attention as a way to use less expensive and more environmentally friendly methods. Among the various CO surrogates, N,N-dimethylformamide (DMF) has been paid greater attention due to its low cost and easy availability. This mini-review gives appealing insights into the application of DMF as a CO surrogate in metal-catalyzed carbonylations; in particular, in the first part we will give a general state of the art of these reactions for the preparation of carbonyl-containing molecules; then, we will take into account all the various synthetic approaches for the metal-catalyzed carbonylative synthesis of heterocycles using DMF as a CO surrogate. Each protocol has been discussed critically in order to screen the best synthetic method and to offer perspective on trends and future directions in this field.

Practical Picture Processing

1974 ◽  
Vol 32 ◽  
pp. 338-339
Author(s):  
T. A. Welton
Keyword(s):  
Radiation Damage ◽  
Coherence Length ◽  
Spatial Information ◽  
State Of The Art ◽  
Coherent Radiation ◽  
The State ◽  
Energy Spread ◽  
Electron Micrograph ◽  
Picture Processing ◽  
Molecular Skeleton

Various authors have emphasized the spatial information resident in an electron micrograph taken with adequately coherent radiation. In view of the completion of at least one such instrument, this opportunity is taken to summarize the state of the art of processing such micrographs. We use the usual symbols for the aberration coefficients, and supplement these with £ and 6 for the transverse coherence length and the fractional energy spread respectively. He also assume a weak, biologically interesting sample, with principal interest lying in the molecular skeleton remaining after obvious hydrogen loss and other radiation damage has occurred.

A Macintosh Interface for the Cameca Camebax-Micro Electron Microprobe

1990 ◽  
Vol 48 (1) ◽  
pp. 438-439
Author(s):  
Carl E. Henderson
Keyword(s):  
Electron Microprobe ◽  
Processing Speed ◽  
Word Processing ◽  
State Of The Art ◽  
Computer Control ◽  
Third Party ◽  
Disk Storage ◽  
The Past ◽  
User Facility ◽  
Instrument Control

Over the past few years it has become apparent in our multi-user facility that the computer system and software supplied in 1985 with our CAMECA CAMEBAX-MICRO electron microprobe analyzer has the greatest potential for improvement and updating of any component of the instrument. While the standard CAMECA software running on a DEC PDP-11/23+ computer under the RSX-11M operating system can perform almost any task required of the instrument, the commands are not always intuitive and can be difficult to remember for the casual user (of which our laboratory has many). Given the widespread and growing use of other microcomputers (such as PC’s and Macintoshes) by users of the microprobe, the PDP has become the “oddball” and has also fallen behind the state-of-the-art in terms of processing speed and disk storage capabilities. Upgrade paths within products available from DEC are considered to be too expensive for the benefits received. After using a Macintosh for other tasks in the laboratory, such as instrument use and billing records, word processing, and graphics display, its unique and “friendly” user interface suggested an easier-to-use system for computer control of the electron microprobe automation. Specifically a Macintosh IIx was chosen for its capacity for third-party add-on cards used in instrument control.

Pyridyl disulfide-based thiol–disulfide exchange reaction: shaping the design of redox-responsive polymeric materials

2020 ◽  
Vol 11 (48) ◽  
pp. 7603-7624
Author(s):  
Ismail Altinbasak ◽  
Mehmet Arslan ◽  
Rana Sanyal ◽  
Amitav Sanyal
Keyword(s):  
Exchange Reaction ◽  
Functional Materials ◽  
Polymeric Materials ◽  
Disulfide Exchange ◽  
Redox Responsive ◽  
Synthetic Approaches

This review provides an overview of synthetic approaches utilized to incorporate the thiol-reactive pyridyl-disulfide motif into various polymeric materials, and briefly highlights its utilization to obtain functional materials.

Current Issues: Advanced Digital Technology for Supervising Graduate Clinicians

2010 ◽  
Vol 20 (1) ◽  
pp. 9-13 ◽  
Author(s):  
Glenn Tellis ◽  
Lori Cimino ◽  
Jennifer Alberti
Keyword(s):  
Real Time ◽  
Digital Technology ◽  
Clinical Training ◽  
State Of The Art ◽  
Clinical Skills ◽  
Slow Motion ◽  
Video Capture ◽  
Microsoft Excel ◽  
Clinical Supervisors ◽  
Training And Supervision

Abstract The purpose of this article is to provide clinical supervisors with information pertaining to state-of-the-art clinic observation technology. We use a novel video-capture technology, the Landro Play Analyzer, to supervise clinical sessions as well as to train students to improve their clinical skills. We can observe four clinical sessions simultaneously from a central observation center. In addition, speech samples can be analyzed in real-time; saved on a CD, DVD, or flash/jump drive; viewed in slow motion; paused; and analyzed with Microsoft Excel. Procedures for applying the technology for clinical training and supervision will be discussed.

Behavioral Genetics: Concepts for Research and Practice in Language Development and Disorders

1995 ◽  
Vol 38 (5) ◽  
pp. 1126-1142 ◽  
Author(s):  
Jeffrey W. Gilger
Keyword(s):  
Language Development ◽  
Behavioral Genetics ◽  
State Of The Art ◽  
Genetic Research ◽  
Great Promise ◽  
Behavioral Genetic ◽  
Fine Grained ◽  
Future Goals ◽  
Current State ◽  
Research Designs

This paper is an introduction to behavioral genetics for researchers and practioners in language development and disorders. The specific aims are to illustrate some essential concepts and to show how behavioral genetic research can be applied to the language sciences. Past genetic research on language-related traits has tended to focus on simple etiology (i.e., the heritability or familiality of language skills). The current state of the art, however, suggests that great promise lies in addressing more complex questions through behavioral genetic paradigms. In terms of future goals it is suggested that: (a) more behavioral genetic work of all types should be done—including replications and expansions of preliminary studies already in print; (b) work should focus on fine-grained, theory-based phenotypes with research designs that can address complex questions in language development; and (c) work in this area should utilize a variety of samples and methods (e.g., twin and family samples, heritability and segregation analyses, linkage and association tests, etc.).

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