Directed, Palladium(II)-Catalyzed Enantioselective anti-Carboboration of Alkenyl Carbonyl Compounds

2019 ◽  
Author(s):  
Zhen Liu ◽  
Xiaohan Li ◽  
Tian Zeng ◽  
Keary Engle
Keyword(s):  
Carbonyl Compounds ◽  
Building Blocks ◽  
New Method ◽  
Carbon Based

A substrate-directed enantioselective <i>anti</i>-carboboration reaction of alkenes has been developed, wherein a carbon based nucleophile and a boron moiety are installed across the C=C bond through a 5- or 6-membered palladacycle intermediate. The reaction is promoted by a palladium(II) catalyst and a mondentate oxzazoline ligand. A range of enantioenriched secondary alkylboronate products were obtained with moderate to high enantioselectivity that could be further upgraded by recrystallization. This work represents a new method to synthesize versatile and valuable alkylboronate building blocks. Building on an earlier mechanistic proposal by Peng, He, and Chen, a revised model is proposed to account for the stereoconvergent nature of this transformation.

Directed, Palladium(II)-Catalyzed Enantioselective anti-Carboboration of Alkenyl Carbonyl Compounds

2019 ◽  
Author(s):  
Zhen Liu ◽  
Xiaohan Li ◽  
Tian Zeng ◽  
Keary Engle
Keyword(s):  
Carbonyl Compounds ◽  
Building Blocks ◽  
New Method ◽  
Carbon Based

A substrate-directed enantioselective <i>anti</i>-carboboration reaction of alkenes has been developed, wherein a carbon based nucleophile and a boron moiety are installed across the C=C bond through a 5- or 6-membered palladacycle intermediate. The reaction is promoted by a palladium(II) catalyst and a mondentate oxzazoline ligand. A range of enantioenriched secondary alkylboronate products were obtained with moderate to high enantioselectivity that could be further upgraded by recrystallization. This work represents a new method to synthesize versatile and valuable alkylboronate building blocks. Building on an earlier mechanistic proposal by Peng, He, and Chen, a revised model is proposed to account for the stereoconvergent nature of this transformation.

A New Method for Oxidation of Various Alcohols to the Corresponding Carbonyl Compounds by UsingN-t-Butylbenzenesulfinimidoyl Chloride

2002 ◽  
Vol 75 (2) ◽  
pp. 223-234 ◽  
Author(s):  
Jun-ichi Matsuo ◽  
Daisuke Iida ◽  
Kazuya Tatani ◽  
Teruaki Mukaiyama
Keyword(s):  
Carbonyl Compounds ◽  
New Method

Carbon-based building blocks for alcohol dehydration membranes with disorder-enhanced water permeability

Carbon ◽  
2017 ◽  
Vol 118 ◽  
pp. 458-466 ◽  
Author(s):  
V. Boffa ◽  
H. Etmimi ◽  
P.E. Mallon ◽  
H.Z. Tao ◽  
G. Magnacca ◽  
...  
Keyword(s):  
Water Permeability ◽  
Building Blocks ◽  
Alcohol Dehydration ◽  
Carbon Based

Processability predictions for mechanically recycled blends of linear polymers

2020 ◽  
Vol 40 (9) ◽  
pp. 771-781
Author(s):  
Janne van Gisbergen ◽  
Jaap den Doelder
Keyword(s):  
Molecular Weight ◽  
Circular Economy ◽  
Melt Flow Index ◽  
Building Blocks ◽  
Experimental Designs ◽  
New Method ◽  
Flow Index ◽  
Linear Polymers ◽  
Combined Method

AbstractRecycling of thermoplastic polymers is an important element of sustainable circular economy practices. The quality of mechanically recycled polymers is a concern. A method is presented to predict the structure and processability of recycled blends of polymers based on processability knowledge of their virgin precursor components. Blending rules at molecular weight distribution level are well established and form the foundation of the new method. Two essential fundamental building blocks are combined with this foundation. First, component and blend structure are related to viscosity via tube theories. Second, viscosity is related to melt flow index via a continuum mechanics approach. Emulator equations are built based on virtual experimental designs for fast forward and reverse calculations directly relating structure to viscosity and processability. The new combined method is compared with empirical blend rules, and shows important similarities and also clear quantitative differences. Finally, the new method is applied to practical recycling quality challenges.

scholarly journals SAATY 1977: THE BUILDING BLOCKS

2017 ◽  
Vol 9 (3) ◽  
Author(s):  
William Wedley
Keyword(s):  
Hierarchical Structures ◽  
Building Blocks ◽  
New Method ◽  
Face Validity ◽  
Ratio Measurement ◽  
Ratio Scales

Saaty’s 1977 article is his first comprehensive publication of the ideas behind AHP. He reveals his creativity in a new method for ratio measurement that includes pairwise ratio matrices, derived ratio scales from those matrices, and checks on the consistency of data.  His ingenuity in using ratio measures is revealed by the use of hierarchical structures to display priorities and then a rescaling of them in a manner that allows synthesis for a composite ratio result. Face validity is provided by many supporting examples and mathematical validity is provided by the solution to many theorems. https://doi.org/10.13033/ijahp.v9i3.532

scholarly journals An expeditious and efficient bromomethylation of thiols: enabling bromomethyl sulfides as useful building blocks

RSC Advances ◽  
2018 ◽  
Vol 8 (43) ◽  
pp. 24654-24659 ◽  
Author(s):  
Carolina Silva-Cuevas ◽  
Ehecatl Paleo ◽  
David F. León-Rayo ◽  
J. Armando Lujan-Montelongo
Keyword(s):  
Free Radical ◽  
Building Blocks ◽  
New Method ◽  
Radical Chemistry ◽  
Synthetic Utility ◽  
Free Radical Chemistry

A new method for the bromomethylation of thiols using paraformaldehyde and HBr/AcOH, minimizes the generation of toxic byproducts. Synthetic utility of α-bromomethyl sulfides was demonstrated through umpolung and free radical chemistry.

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