scholarly journals The Use of Polymer Supports in Organic Synthesis. II. The Syntheses of Monoethers of Symmetrical Diols

1973 ◽  
Vol 51 (15) ◽  
pp. 2452-2456 ◽  
Author(s):  
Jack Y. Wong ◽  
Clifford C. Leznoff
Keyword(s):  
Organic Synthesis ◽  
Support System ◽  
Functional Group ◽  
Polymer Support ◽  
Reaction Conditions ◽  
Polymer Supports ◽  
Unique Method ◽  
Insoluble Polymer

An insoluble polymer support system was used as a unique method of blocking one functional group of a completely symmetrical difunctional compound. The monotetrahydropyranyl and monotrityl ethers of the symmetrical diols, HO—(CH2)n—OH, where n = 2,4,6,8, and 10, were prepared. Reaction conditions for the preparation of the monotetrahydropyranyl ether of 1,10-decanediol were optimized.

scholarly journals The Use of Polymer Supports in Organic Synthesis. III. Selective Chemical Reactions on One Aldehyde Group of Symmetrical Dialdehydes

1973 ◽  
Vol 51 (22) ◽  
pp. 3756-3764 ◽  
Author(s):  
Clifford C. Leznoff ◽  
Jack Y. Wong
Keyword(s):  
Aldol Condensation ◽  
Aluminum Hydride ◽  
Aldehyde Group ◽  
Polymer Support ◽  
High Yield ◽  
Yield Reduction ◽  
Polymer Supports ◽  
Acid Cleavage ◽  
Unique Method ◽  
Insoluble Polymer

An insoluble polymer support system incorporating a diol functional group was prepared. The symmetrical dialdehydes, terephthalaldehyde and isophthalaldehyde, were attached to the polymer through acetal formation, constituting a unique method of blocking one aldehyde group of symmetrical dialdehydes. The free aldehyde group was reacted with hydroxylamine to give the mono-oximes of the terephthalaldehyde and isophthalaldehyde upon acid cleavage from the polymer. Similarly, the polymer bound aldehydes were reacted with Wittig reagents to give p- and m-formylstilbenes and 1-p- and -m-formyl-phenyl-4-phenyl-1,3-butadienes. The crossed aldol condensation of acetophenone with the symmetrical dialdehydes gave the 3-p- and -m-formylphenyl-1-phenyl-2-propene-1-ones (formylchalcones) in high yield. The Grignard reaction of phenylmagnesium bromide on the polymer bound aldehyde gave(p- and m-formylphenyl)phenylcarbinol in quantitative yield. Reduction of the polymer bound free aldehydes with sodium bis(2-methoxyethoxy)-aluminum hydride gave p- and m-hydroxymethylbenzaldehydes. Similarly the mixed benzoin condensation of polymer bound terephthalaldehyde and isophthalaldehyde gave p- and m-formylbenzils.

scholarly journals The Use of Polymer Supports in Organic Synthesis. The Synthesis of Monotrityl Ethers of Symmetrical Diols

1972 ◽  
Vol 50 (17) ◽  
pp. 2892-2893 ◽  
Author(s):  
Clifford C. Leznoff ◽  
Jack Y. Wong
Keyword(s):  
Organic Synthesis ◽  
Acid Chloride ◽  
Functional Group ◽  
Selective Synthesis ◽  
Polymer Supports ◽  
Unique Method

A modified Merrifield polymer containing acid chloride groups was used in the selective synthesis of the monotrityl ethers of the symmetrical diols, HO—(CH2)n—OH, where n = 2, 4, 6, 8, and 10. This procedure constitutes a unique method of blocking one functional group of a completely symmetrical difunctional compound.

Modern Organic Synthesis in the Laboratory

2008 ◽  
Author(s):  
Jie Jack Li ◽  
Chris Limberakis ◽  
Derek A. Pflum
Keyword(s):  
Organic Chemistry ◽  
Graduate Students ◽  
Organic Synthesis ◽  
Functional Group ◽  
Bond Formation ◽  
Reaction Conditions ◽  
Carbon Bond ◽  
Oxidation Reduction ◽  
Carbon Carbon Bond ◽  
Daunting Task

Searching for reaction in organic synthesis has been made much easier in the current age of computer databases. However, the dilemma now is which procedure one selects among the ocean of choices. Especially for novices in the laboratory, it becomes a daunting task to decide what reaction conditions to experiment with first in order to have the best chance of success. This collection intends to serve as an "older and wiser lab-mate" one could have by compiling many of the most commonly used experimental procedures in organic synthesis. With chapters that cover such topics as functional group manipulations, oxidation, reduction, and carbon-carbon bond formation, Modern Organic Synthesis in the Laboratory will be useful for both graduate students and professors in organic chemistry and medicinal chemists in the pharmaceutical and agrochemical industries.

Ligand-Driven Advances in Iridium Catalyzed sp3 C-H Borylation: 2,2’-Dipyridylarylmethane

Synlett ◽  
2020 ◽  
Author(s):  
Margaret R Jones ◽  
Nathan D. Schley
Keyword(s):  
Recent Work ◽  
Organic Synthesis ◽  
Functional Group ◽  
Reaction Conditions ◽  
Recent Advances ◽  
Additional Ligand ◽  
Limited Application ◽  
Hydrocarbon Substrates ◽  
Phenanthroline Ligands

The field of catalytic C-H borylation has grown considerably since its founding, providing a means for the preparation of synthetically versatile organoborane products. While sp2 C-H borylation methods have found widespread and practical use in organic synthesis, the analogous sp3 C-H borylation reaction remains challenging and has seen limited application. Existing catalysts are often hindered by incomplete consumption of the diboron reagent, poor functional group tolerance, harsh reaction conditions, and the need for excess or neat substrate. These challenges acutely affect C-H borylation chemistry of unactivated hydrocarbon substrates, which has lagged in comparison to methods for the C-H borylation of activated compounds. Herein we discuss recent advances in sp3 C-H borylation of undirected substrates in the context of two particular challenges: (1) utilization of the diboron reagent and (2) the need for excess or neat substrate. Our recent work on the application of dipyridylarylmethane ligands in sp3 C-H borylation has allowed us to make contributions in this space and has presented an additional ligand scaffold to supplement traditional phenanthroline ligands.

scholarly journals Iodonium-Catalyzed Carbonyl–Olefin Metathesis Reactions

Synlett ◽  
2019 ◽  
Vol 30 (17) ◽  
pp. 1966-1970 ◽  
Author(s):  
Giulia Oss ◽  
Thanh Vinh Nguyen
Keyword(s):  
Transition Metal ◽  
Organic Compounds ◽  
Organic Synthesis ◽  
Olefin Metathesis ◽  
Lewis Acids ◽  
Functional Group ◽  
Iodine Monochloride ◽  
Metathesis Reaction ◽  
Reaction Conditions ◽  
Recent Developments

The carbonyl–olefin metathesis reaction has become increasingly important in organic synthesis due to its versatility in functional group interconversion chemistry. Recent developments in the field have identified a number of transition-metal and organic Lewis acids as effective catalysts for this reaction. Herein, we report the use of simple organic compounds such as N-iodosuccinimide or iodine monochloride to catalyze the carbonyl–olefin metathesis process under mild reaction conditions. This work broadens the scope of this chemical transformation to include iodonium sources as simple and practical catalysts.

The use of polymer supports in organic synthesis. V. The preparation of monoacetates of symmetrical diols

1976 ◽  
Vol 54 (6) ◽  
pp. 935-942 ◽  
Author(s):  
Thomas M. Fyles ◽  
Clifford C. Leznoff
Keyword(s):  
Organic Synthesis ◽  
Acetyl Chloride ◽  
Methyl Benzoate ◽  
Styrene Copolymer ◽  
Polymer Supports ◽  
Acid Cleavage ◽  
Insoluble Polymer

A 2% cross-linked divinylbenzene–styrene copolymer was directly lithiated with n-butyllithium in the presence of N,N,N′,N′-tetramethylethylenediamine. The lithiated polymer on reaction with a benzophenone gave an insoluble polymer-bound trityl alcohol. Further reaction with acetyl chloride gave a polymer-bound trityl chloride which, on treatment with the primary symmetrical diols 1,10-decanediol, 1,7-heptanediol, and 1,4-butanediol, gave mostly symmetrical diols monoblocked by insoluble polymer-bound trityl groups. Acetylation followed by acid cleavage from the polymer gave the monoacetates of 1,10-decanediol, 1,7-heptanediol, and 1,4-butanediol and some recovered diols. The recovered polymer can be efficiently recycled. The quantity of recovered diol was related to the problem of 'double-binding' of the symmetrical diols to the polymer-bound trityl groups. The extent of 'double-binding' could be greatly reduced by the use of polymer-bound trityl chloride prepared via the lithiated polymer and methyl benzoate or phosgene.

Biocatalysis for Sustainable Organic Synthesis

2004 ◽  
Vol 57 (4) ◽  
pp. 281 ◽  
Author(s):  
Roger A. Sheldon ◽  
Fred van Rantwijk
Keyword(s):  
Organic Synthesis ◽  
Functional Group ◽  
Solvent System ◽  
Fine Chemicals ◽  
Reaction Conditions ◽  
Organic Syntheses ◽  
Recent Advances ◽  
Cascade Processes

Biocatalysis offers mild reaction conditions, an environmentally attractive catalyst–solvent system, high activities, and chemo-, regio-, and stereoselectivities, while the use of enzymes generally circumvents the need for functional group activation and avoids protection/deprotection steps required in traditional organic syntheses. This review, using β-lactam antibiotics as an example, discusses recent advances in biocatalysis research towards the goal of ‘green’ methodologies for the manufacture of (fine) chemicals and the emulation of a cell's enzymatic cascade processes.

scholarly journals Dioxasilepanyl Group as a Versatile Organometallic Unit: Studies in Stability, Reactivity, and Utility

2021 ◽  
Author(s):  
Hayate Saito ◽  
Jun Shimokawa ◽  
Hideki Yorimitsu
Keyword(s):  
Functional Groups ◽  
Organic Synthesis ◽  
Functional Group ◽  
Reaction Conditions ◽  
Multistep Synthesis

Organic synthesis is orchestrated based on precise choices of functional groups and reactions employed. In a multistep synthesis, an ideal functional group should be orthogonal to various reaction conditions and...

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