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Deprotection

Distribution by Scientific Domains
Chemistry91%
Polymers and Materials Science8%
Distribution within Chemistry
Organic Chemistry65%
General & Introductory Chemistry20%
7 Other Subdomains15%

Kinds of Deprotection

  • catalytic deprotection
  • efficient deprotection
    		•
  • oxidative deprotection
  • selective deprotection
    		•
  • subsequent deprotection

    • Terms modified by Deprotection

  • deprotection method
    		•
  • deprotection step
    		•

    Selected Abstracts

    Hydrosilanes Are Not Always Reducing Agents for Carbonyl Compounds, II: Ruthenium-Catalyzed Deprotection of tert -Butyl Groups in Carbamates, Carbonates, Esters, and Ethers

    EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 6 2010
    Shiori Hanada
    Abstract Hydrosilanes act as a reagent to cleave the C,O bond of OtBu groups in carbamates, carbonates, esters, and ethers by catalysis of a triruthenium cluster. The reaction offers a novel deprotection method for OtBu groups under neutral conditions, showing unique selectivities that have never been accomplished with conventional Brønsted or Lewis acidic promoters. Possible mechanisms for C,O cleavage are discussed on the basis of NMR spectroscopic analysis. [source]

    Reinvestigation of the Mechanism of gem -Diacylation: Chemoselective Conversion of Aldehydes to Various gem -Diacylates and Their Cleavage under Acidic and Basic Conditions

    EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 2 2005
    Veerababurao Kavala
    Abstract The mechanism of gem -diacylate formation has been studied extensively using tetrabutylammonium tribromide (TBATB) as the catalyst. The reaction proceeds by a nucleophilic attack of an anhydride on an aldehydic carbonyl group, nucleophilic attack of the hemiacylate intermediate on a second molecule of the anhydride, followed by an intermolecular attack of a second acetate group to regenerate the anhydride. gem -Diacylates of various aliphatic and aromatic aldehydes were obtained directly from the reaction of a variety of aliphatic and aromatic acid anhydrides in the presence of a catalytic quantity of tetrabutylammonium tribromide (TBATB) under solvent-free conditions. A significant electronic effect was observed during its formation as well as deprotection to the corresponding aldehyde. Chemoselective gem -diacylation of the aromatic aldehyde containing an electron-donating group has been achieved in the presence of an aldehyde containing an electron-withdrawing group. Deprotection of the gem -diacylate to the parent carbonyl compound can be accomplished in methanol in presence of the same catalyst. Here again, chemoselective deprotection of the gem -diacylate of a substrate containing an electrondonating group has been achieved in the presence of a substrate containing an electron-withdrawing group. Both the acid and base stability order of the various gem -diacylates examined follow a similar order. The stability order determined from the present study is: gem -dibenzoate > gemdipivalate > gem -diisobutyrate > gem -diacetate > gem -dipropionate. All the gem -diacylals are more stable under basic conditions than acidic condition. No correlation was found between the stability order and the pKa's of the corresponding acids; rather, the stability order is directly related to the steric crowding around the carbonyl carbon. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005) [source]

    Highly Shape-Selective, Biomimetic, and Efficient Deprotection of Carbonyl Compounds Masked as Ethylene Acetals or Dioxolanes Produced from 1,2-Ethanediol

    EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 18 2003
    Hong-Bing Ji
    Abstract A simple, mild, efficient, and organic solvent-free biochemical approach for the deprotection of carbonyl compounds protected as 1,3-dioxolanes through the use of cyclodextrins as catalysts has been developed. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) [source]

    De Novo Synthesis of Racemic Spirocyclopropane-Annelated 2-Deoxyhexose Derivatives

    EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 3 2003
    Armin de Meijere
    Abstract High-pressure-induced inverse-electron-demand hetero-Diels,Alder reactions of ethyl trans -4-ethoxy-2-oxo-3-butenoate (2a) and methyl trans -4-benzyloxy-2-oxo-3-butenoate (2b) with benzyl (cyclopropylidenemethyl) ether (1) each yielded mixtures of two separable diastereomeric esters 7a (64%) and 7b (80%) which, in three subsequent steps, led to the 3-ethylated and 3-benzylated ,- and ,-anomeric benzyl spiro[2-deoxy-(D,L)- arabino -hexopyranoside-2,1,-cyclopropanes] ,- 10a,b and ,- 10a,b, respectively. The relative configuration of ,- 10a was proved by an X-ray crystal structure analysis. Deprotection of ,- 10b was achieved by Pd-catalyzed hydrogenation in dimethylacetamide leading to spiro[2-deoxy-,/,-2-(D,L)- arabino -hexopyranoside-2,1,-cyclopropane] (4). (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) [source]

    On the Synthesis and Selective Deprotection of Low-Generation Dendrons with Orthogonally Protected Peripheral Amine Groups and a Possible Impact of the Deprotection Conditions on the Stability of Dendronized Polymers' Skeletons

    HELVETICA CHIMICA ACTA, Issue 11 2006
    Rabie Al-Hellani
    Abstract The synthesis of first- and second-generation dendrons with defined ratios of orthogonally protected amine groups in the periphery ((benzyloxy)carbonyl (Cbz) and (tert -butoxy)carbonyl (Boc) protection) and the degree to which they can be selectively removed are described. The reaction conditions required for these deprotections were applied to methacrylic acid (=,2-methylprop-2-enoic acid) based dendronized polymers carrying the same peripheral protecting groups to investigate whether they have any detrimental interference with the polymer skeleton. Specifically it was explored whether dendrons attached to the backbone could possibly be cleaved off as a whole (de-dendronization). Finally it was investigated how de-dendronizations can be used for quantifying both the dendron-structure perfection and the polymer-backbone configurations. [source]

    7-Iodo-5-aza-7-deazaguanine: Syntheses of Anomeric D - and L -Configured 2-Deoxyribonucleosides

    HELVETICA CHIMICA ACTA, Issue 9 2004
    Wenqing Lin
    Iodination of N2 -isobutyryl-5-aza-7-deazaguanine (7) with N -iodosuccinimide (NIS) gave 7-iodo- N2 -isobutyryl-5-aza-7-deazaguanine (8) in a regioselective reaction (Scheme,1). Nucleobase-anion glycosylation of 8 with 2-deoxy-3,5-di- O -toluoyl- , - D - or , - L - erythro -pentofuranosyl chloride furnished anomeric mixtures of D - and L -nucleosides. The anomeric D -nucleosides were separated by crystallization to give the , - D -anomer and , - D -anomer with excellent optical purity. Deprotection gave the 7-iodo-5-aza-7-deazaguanine 2,-deoxyribonucleosides 3 (, - D; ,99% de) and 4 (, - D; ,99% de). The reaction sequence performed with the D -series was also applied to L -nucleosides to furnish compounds 5 (, - L; ,99% de) and 6 (, - L; ,95% de). [source]

    Effective High-Pressure Cleavage of Sterically Hindered Steroid Esters

    HELVETICA CHIMICA ACTA, Issue 6 2004
    Wojciech Kroszczy
    A simple and effective method to deprotect of sterically hindered steroid esters is described. Deprotection was carried out in MeOH in the presence of a catalytic amount of Et3N under high-pressure conditions. Enzymatic, anionite, and high-pressure methods are compared. [source]

    Convergent Synthesis of Both Enantiomers of 4-Hydroxypent-2-ynoic Acid Diphenylamide for a Thrombin Receptor Antagonist Sch,530348 and Himbacine Analogues

    ADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 14-15 2009
    Alex Zaks
    Abstract Sch,530348 and many himbacine analogues were prepared by using 4-hydroxypent-2-ynoic acid diphenylamide as the only chiral material. We developed deracemization methods to prepare both enantiomers of this propargyl alcohol. These methods involved a resolution followed by inversion. The objective for the resolution step was to obtain the desired enantiomer as an ester, and undesired enantiomer as an alcohol. With (R)-selective lipase, this was achieved by transesterifcation for (R)-alcohol, and ester hydrolysis for (S)-alcohol. The undesired enantiomer was inverted through the corresponding tosylate to yield the desired enantiomer as the ester. Deprotection of the ester gave enantiopure alcohol as the product. These methods not only overcame the 50% yield limit in resolution, but also eliminated the need to remove the undesired enantiomer. [source]

    Synthesis and evaluation of two uncharged 99mTc-labeled derivatives of thioflavin-T as potential tracer agents for fibrillar brain amyloid

    JOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 6 2009
    K. Serdons
    Abstract Thioflavin-T is a fluorescent dye for in vitro detection of fibrillar amyloid ,, a protein found in the brain of patients suffering from Alzheimer's disease. We synthesized and biologically evaluated two uncharged 99mTc-labeled derivatives of thioflavin-T. The precursors for labeling were synthesized by coupling an S,S, -bis-triphenylmethyl- N - tert -butoxycarbonyl bis-amino-bis-thiol tetradentate ligand via a propoxy spacer to 2-(4,-aminophenyl)-1,3-benzothiazole at the 6-position or the 2,-position. Deprotection and labeling with 99mTc were done via a one-pot procedure (15% yield) after which the labeled compound was isolated by high performance liquid chromatography (LC). LC in combination with mass spectrometry (MS) was used for identity confirmation of the labeled compounds. Results of electrophoresis and log,P determination supported the assumption that the radiolabeled compounds could cross the blood,brain barrier by passive diffusion. However, in normal mice both compounds showed a low brain uptake 2,min post injection. They were mainly excreted through the hepatobiliary system, with some accumulation in the stomach. Sixty minutes after intravenous injection, 37% of the 99mTc-activity in the blood corresponded to the original compound. In view of the low brain uptake, it is concluded that the studied 99mTc-labeled derivatives of thioflavin-T are not suitable as tracer agents for in vivo visualization of amyloid in brain. Copyright © 2009 John Wiley & Sons, Ltd. [source]

    Synthesis of 13C3 -hydroxyacetone

    JOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 9 2003
    Christopher W. Dicus
    Abstract 13C3 -Hydroxyacetone is prepared in three steps from 13C2 -2-bromoacetic acid. Bromide displacement by sodium p -methoxybenzyl alkoxide followed by treatment of the carboxylic acid with 13C-methyl lithium furnishes PMB-protected hydroxyacetone. Deprotection using DDQ delivers the title compound. Copyright © 2003 John Wiley & Sons, Ltd. [source]

    Synthesis and properties of new fluorinated polymers bearing pendant imidazole groups for fuel cell membranes operating over a broad relative humidity range

    JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 1 2010
    Guillaume Frutsaert
    Abstract New alternating copolymers comprising a chlorotrifluorinated backbone and imidazole-terminated pendant ethylene oxide groups have been prepared with a view to their use as a component of proton-conducting membranes in polymer electrolyte fuel cells. A vinyl ether containing an imidazole (Imi) function protected by a benzyl group (BVI) was first synthesized in a three-step reaction. It was then copolymerized in solution with chlorotrifluoroethylene (CTFE) by conventional radical copolymerization leading to alternating poly(BVI-alt-CTFE) copolymers in good yields. Deprotection of the benzyl group under hydrogen produced a chlorotrifluorinated poly(Imi-alt-CTFE) copolymer. The polymer was subsequently used to form blend membranes with sulfonated poly(ether ether ketone) (sPEEK). The conductivity of blend membranes of poly (Imi-alt-CTFE) with sPEEK lies in the range of 4,10 mS cm,1 at 40,70 °C and, for blend membranes rich in poly(Imi-alt-CTFE), is little dependent on relative humidity between 30 and 100%. It is surmised that the polymer and membrane composition favor microstructural phase separation into chlorotrifluorinated polymer backbone domains and regions in which imidazole groups are clustered. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 223,231, 2010 [source]

    ChemInform Abstract: Oxidation and Deprotection of Primary Benzylamines by Visible Light Flavin Photocatalysis.

    CHEMINFORM, Issue 40 2010
    Robert Lechner
    Abstract The oxidation of a variety of benzylamines and structurally related compounds is investigated. [source]

    ChemInform Abstract: 1-Decanethiol, a New Reagent for the Odorless Deprotection of Aryl Methyl Ethers.

    CHEMINFORM, Issue 39 2010
    Bhima Kale
    Abstract The practical method allows an essentially odorless aqueous work-up. [source]

    ChemInform Abstract: Influence of the Gas Atmosphere on the Deprotection of (Z)-,-Hydroxy-,,,-Unsaturated Esters.

    CHEMINFORM, Issue 7 2010
    Irakusne Lopez
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

    ChemInform Abstract: Practical, Environment-Benign and Atom Economic KOAc-Catalyzed Deprotection of Aryl TIPS Ethers under Mild Fluoride-Free Conditions.

    CHEMINFORM, Issue 52 2009
    Bing Wang
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

    ChemInform Abstract: NbCl5 -Mediated Deprotection of Methoxy Methyl Ether.

    CHEMINFORM, Issue 44 2009
    J. S. Yadav
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

    ChemInform Abstract: Selective Deprotection of Silyl Ethers with Sodium Periodate.

    CHEMINFORM, Issue 43 2009
    Jun Li
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

    ChemInform Abstract: KBrO3/MoO3: An Efficient Reagent System for the Oxidative Deprotection of Semicarbazones, 1,1-Diacetates and Acetals.

    CHEMINFORM, Issue 36 2009
    Farhad Shirini
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

    ChemInform Abstract: One-Pot N-Arylation of Indoles Directly from N-Arylsulfonylindoles via Consecutive Deprotection and SNAr Reactions with Activated Aryl Halides.

    CHEMINFORM, Issue 36 2009
    Hui Xu
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

    ChemInform Abstract: Microwave-Assisted N-Boc Deprotection under Mild Basic Conditions Using K3PO4·H2O in MeOH.

    CHEMINFORM, Issue 22 2009
    Srinivasa Reddy Dandepally
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

    ChemInform Abstract: A Mild and Efficient Approach for the Selective Deprotection of Benzyl and Phenyl Trimethylsilyl Ethers in 1-Butyl-3-methylimidazolium Chloride.

    CHEMINFORM, Issue 12 2009
    Ahmad Shaabani
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

    ChemInform Abstract: Catalytic Asymmetric Deprotection of Phosphine Boranes and Sulfides as a Route to P-Stereogenic Compounds.

    CHEMINFORM, Issue 51 2008
    Jonathan J. Gammon
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

    ChemInform Abstract: Efficient Oxidative Deprotection of Trimethylsilyl, Tetrahydropyranyl and Methoxymethyl Ethers under Solvent-Free Conditions.

    CHEMINFORM, Issue 46 2008
    Farhad Shirini
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

    ChemInform Abstract: Ionene-Supported Peroxodisulfates: Polymeric Reagents for the Oxidative Deprotection of TMS and THP Ethers and Oxidative Cleavage of the C=N Bond in Water.

    CHEMINFORM, Issue 33 2008
    Moslem Mansour Lakouraj
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

    ChemInform Abstract: Unexpected Tosyl Deprotection During Osmium Catalyzed Dihydroxylation.

    CHEMINFORM, Issue 18 2008
    Frederic Batt
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

    ChemInform Abstract: Remarkable Solvent Effect on Pd(0)-Catalyzed Deprotection of Allyl Ethers Using Barbituric Acid Derivatives: Application to Selective and Successive Removal of Allyl, Methallyl, and Prenyl Ethers.

    CHEMINFORM, Issue 18 2008
    Hirokazu Tsukamoto
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

    ChemInform Abstract: Indium- and Zinc-Mediated Barbier-Type Allylations of an N,N-(Dimethylsulfamoyl)-Protected Aldimine and Subsequent Deprotection.

    CHEMINFORM, Issue 3 2008
    Sara Kaellstroem
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

    Reductive Deprotection of Silyl Groups with Wilkinson,s Catalyzed/Catechol Borane.

    CHEMINFORM, Issue 45 2007
    Pranav Patel
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source]

    Solid-Supported Acids as Mild and Versatile Reagents for the Deprotection of Aromatic Ethers.

    CHEMINFORM, Issue 44 2007
    Poonsakdi Ploypradith
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source]

    Mesoporous Aluminosilicate Promoted Protection and Deprotection of Carbonyl Compounds.

    CHEMINFORM, Issue 43 2007
    Mathew W. C. Robinson
    Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source]