scholarly journals Catalyst-Controlled Stereoselective Olefin Metathesis as a Principal Strategy in Multistep Synthesis Design: A Concise Route to (+)-Neopeltolide

2014 ◽  
Vol 54 (1) ◽  
pp. 215-220 ◽  
Author(s):  
Miao Yu ◽  
Richard R. Schrock ◽  
Amir H. Hoveyda
Keyword(s):  
Olefin Metathesis ◽  
Synthesis Design ◽  
Multistep Synthesis

RetroBioCat: Computer-Aided Synthesis Planning for Biocatalytic Reactions and Cascades

2020 ◽  
Author(s):  
William Finnigan ◽  
Lorna J. Hepworth ◽  
Nicholas J. Turner ◽  
Sabine Flitsch
Keyword(s):  
Organic Chemistry ◽  
Computer Aided Design ◽  
Selective Synthesis ◽  
Test Set ◽  
Synthesis Design ◽  
Computer Aided ◽  
Synthesis Planning ◽  
Enzymatic Cascades ◽  
Target Molecules ◽  
Aided Design

As the enzyme toolbox for biocatalysis has expanded, so has the potential for the construction of powerful enzymatic cascades for efficient and selective synthesis of target molecules. Additionally, recent advances in computer-aided synthesis planning (CASP) are revolutionizing synthesis design in both synthetic biology and organic chemistry. However, the potential for biocatalysis is not well captured by tools currently available in either field. Here we present RetroBioCat, an intuitive and accessible tool for computer-aided design of biocatalytic cascades, freely available at retrobiocat.com. Our approach uses a set of expertly encoded reaction rules encompassing the enzyme toolbox for biocatalysis, and a system for identifying literature precedent for enzymes with the correct substrate specificity where this is available. Applying these rules for automated biocatalytic retrosynthesis, we show our tool to be capable of identifying promising biocatalytic pathways to target molecules, validated using a test-set of recent cascades described in the literature.

Catalytic Carbonyl-Olefin Metathesis of Aliphatic Ketones: Iron(III) HomoDimers as Lewis Acidic Superelectrophiles

2018 ◽  
Author(s):  
Haley Albright ◽  
Paul S. Riehl ◽  
Christopher C. McAtee ◽  
Jolene P. Reid ◽  
Jacob R. Ludwig ◽  
...  
Keyword(s):  
Lewis Acid ◽  
Olefin Metathesis ◽  
Acid Activation ◽  
Lewis Acid Catalysts ◽  
Distinct Mode ◽  
Aliphatic Ketones ◽  
Carbon Carbon Bond ◽  
Metathesis Reactions ◽  
Acid Catalyzed

<div>Catalytic carbonyl-olefin metathesis reactions have recently been developed as a powerful tool for carbon-carbon bond</div><div>formation. However, currently available synthetic protocols rely exclusively on aryl ketone substrates while the corresponding aliphatic analogs remain elusive. We herein report the development of Lewis acid-catalyzed carbonyl-olefin ring-closing metathesis reactions for aliphatic ketones. Mechanistic investigations are consistent with a distinct mode of activation relying on the in situ formation of a homobimetallic singly-bridged iron(III)-dimer as the active catalytic species. These “superelectrophiles” function as more powerful Lewis acid catalysts that form upon association of individual iron(III)-monomers. While this mode of Lewis acid activation has previously been postulated to exist, it has not yet been applied in a catalytic setting. The insights presented are expected to enable further advancement in Lewis acid catalysis by building upon the activation principle of “superelectrophiles” and broaden the current scope of catalytic carbonyl-olefin metathesis reactions.</div>

A Design of Experiment Approach to the Synthesis of Alendronate-incorporated Hydroxyapatite

2018 ◽  
Vol 69 (8) ◽  
pp. 1944-1948 ◽  
Author(s):  
Adina Turcu Stiolica ◽  
Maria Viorica Bubulica ◽  
Oana Elena Nicolaescu ◽  
Octavian Croitoru ◽  
Mariana Popescu ◽  
...  
Keyword(s):  
Process Parameters ◽  
Design Of Experiment ◽  
Calcium Nitrate ◽  
Chemical Precipitation ◽  
Synthesis Temperature ◽  
Ripening Time ◽  
Synthesis Design ◽  
N2 Atmosphere ◽  
Addition Rate ◽  
Incorporation Efficiency

A design of experiment (DoE) approach is presented for the optimization of Alendronate-hydroxyapatite nanoparticles� synthesis. The synthesis was performed using the chemical precipitation technique from calcium nitrate, diammonium hydrogen phosphate and alendronate. Synthesis temperature, reactant addition rate and ripening time were chosen as the most relevant experimental factors for our synthesis. Design of Experiments was used in order to measure these conclusive process parameters and their effect on controlling some final nanoparticles parameters, such us: alendronate incorporation efficiency (IncorporationEfficiency, %), hydroxyapatite crystallite size (Size_XRD, nm), hydroxyapatite particle size distribution (Size_DLS, �). Our study found that better HA-AL incorporation efficiency and small nonoparticles can be obtained using the following chemical process parameters: reaction temperature 30oC or smaller, ripening time 108h and addition rate 0.1mol/min. The analysis of more than one nanoparticles characteristics was possible using DoE software, MODDE 9.1. Thus, hydroxyapatite-alendronate incorporation efficiency should be expected to increase with decreasing temperature below 300C, increasing the maturate time at least 108h, at an addition rate of 0.1mol/min, in an N2 atmosphere. The same conditions will ensure nanoparticles small size that would be more desirable for the application of implants.

Solid Supported Ruthenium Complexes for Olefin Metathesis

2013 ◽  
Vol 17 (22) ◽  
pp. 2592-2608 ◽  
Author(s):  
Fatma Hamad ◽  
Cheng Kai ◽  
Yuan Cai ◽  
Yu Xie ◽  
Yin Lu ◽  
...  
Keyword(s):  
Olefin Metathesis ◽  
Ruthenium Complexes

Olefin Metathesis over Mo–exchanged Zeolites: A Computational Review

2014 ◽  
Vol 4 (2) ◽  
pp. 216-230 ◽  
Author(s):  
Xin Li ◽  
Jing Guan ◽  
Gang Yang
Keyword(s):  
Olefin Metathesis
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