Β-azido Alcohols Research Articles

ChemInform Abstract: Stereoselective Production of β-Amino Alcohols and β-Thioacyl Alcohols via an Application of the Non-Aldol Aldol Process.

Abstract The mesylates used as protecting groups to permit the formation of bis(polypropionates) via the non-aldol aldol process can be easily displaced with good nucleophiles, e.g., azide, thioacetate, acetate, to generate β-azido (and β-amino) alcohols, β-thioacyl alcohols, and aldols of the opposite chirality, e.g., syn isomers afford anti products. Thus the anti mesylate 15 affords the all-anti mzido aldol system 16 in good yield.

Tetramethylguanidinium Azide (TMGA) - A Versatile Azidation Agent

Organic azides have been widely used in synthesis, especially for the construction of heterocyclic systems, and as precursors of the primary amino group. [1] One method to incorporate the azide moiety into organic compounds is to use tetramethylguanidinium azide as the azidation agent. Tetramethylguanidinium azide (TMGA, TMGN3) introduced by Papa [2] is commercially available, stable, non-toxic, and safe in use. [3] TMGA is a colorless hygroscopic solid, which is soluble in organic solvents (chloroform, dichloromethane, acetonitrile, nitromethane, DMF, acetone) and water; it is insoluble in diethyl ether and THF. The standard procedure for the preparation of TMGA involves the action of hydrazoic acid (HN3) on tetramethylguanidine in ether. [2] The use of TMGA allows the introduction of the azido group under very mild non-aqueous conditions; however, it is not recommended to use halogenated solvents because explosive azidomethane species may be formed during the reaction. [3] [4] TMGA is frequently used as a source of azide, in nucleophilic addition, substitution, azidolysis of epoxides, and heterocyclic ring formation. [5] It has been successfully used for the synthesis of alkyl, [2] alkenyl, [6] propargyl, [7] heteroaryl, [8] acyl, [9] phosphinic, [10] and sulfonyl azides [11] as well as for the preparation of tert-butyl azidoformate, [12] tetrazoles, [13] β-azido alcohols, [14] α-azido ketones [15] and α-amino acid derivatives. [16]

Anhydrous Titanium(III) chloride as a New Lewis-Acid Catalyst for Ring Opening of Epoxides with Aromatic Amines

Anhydrous titanium(III) chloride was found to be a simple and efficient Lewis acid catalyst for ring opening of epoxides at ambient temperature. The reaction proceeded smoothly with anilines as well as azide ion as nucleophiles to give the corresponding β-amino alcohols and β-azido alcohols in moderate to good yields.

Pd‐Catalyzed Oxidative Kinetic Resolution of 2‐Azido‐1‐arylethanols.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Chemoenzymatic synthesis of ( R)- and ( S)-tembamide, aegeline and denopamine by a one-pot lipase resolution protocol

An efficient synthesis of optically active β-azido alcohols from their ketoazides by a one-pot reduction and an in situ lipase resolution protocol is described. The synthetic utility of this procedure has been illustrated by its application in the practical synthesis of both enantiomers of the natural hydroxyamides, tembamide, aegeline and the cardiac drug denopamine, with high enantioselectivities.

Dynamic Kinetic Resolution of β-Azido Alcohols. An Efficient Route to Chiral Aziridines and β-Amino Alcohols.

ADVERTISEMENT RETURN TO ISSUEPREVAddition/CorrectionORIGINAL ARTICLEThis notice is a correctionDynamic Kinetic Resolution of β-Azido Alcohols. An Efficient Route to Chiral Aziridines and β-Amino Alcohols.Oscar Pàmies and Jan-E. BäckvallCite this: J. Org. Chem. 2002, 67, 4, 1418Publication Date (Web):January 15, 2002Publication History Published online15 January 2002Published inissue 1 February 2002https://doi.org/10.1021/jo0129531Copyright © 2002 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views496Altmetric-Citations3LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (16 KB) Get e-Alerts Get e-Alerts

Ring Opening of Epoxides and Aziridines with Sodium Azide using Oxone®in Aqueous Acetonitrile: A Highly Regioselective Azidolysis Reaction

A wide variety of epoxides and aziridines were converted to the corresponding β-azido alcohols and β-azido amines with sodium azide using Oxone® in aqueous acetonitrile. The reactions were highly regioselective and efficient with excellent yields at room temperature under mild reaction conditions.

Dynamic kinetic resolution of beta-azido alcohols. An efficient route to chiral aziridines and beta-amino alcohols.

Enzymatic resolution of beta-azido alcohols in combination with ruthenium-catalyzed alcohol isomerization led to a successful dynamic kinetic resolution. A variety of racemic beta-azido alcohols were efficiently transformed to the corresponding enantiomerically pure acetates (ee up to 99% and conversion up to 98%). The synthetic utility of this procedure has been illustrated by the practical synthesis of (S)-propanolol I and (R)-beta-azido-alpha-(4-methoxyphenyl)ethanol ((R)-1c), a direct precursor of denopamine II.

Stereoselective production of β-amino alcohols and β-thioacyl alcohols via an application of the non-aldol aldol process

The mesylates used as protecting groups to permit the formation of bis(polypropionates) via the non-aldol aldol process can be easily displaced with good nucleophiles, e.g., azide, thioacetate, acetate, to generate β-azido (and β-amino) alcohols, β-thioacyl alcohols, and aldols of the opposite chirality, e.g., syn isomers afford anti products. Thus the anti mesylate 15 affords the all-anti mzido aldol system 16 in good yield.

Reactions of 2-Substituted Epichlorohydrins

Abstract 2-Substituted epichlorohydrins have been synthesized by starting with 1,2-dichloro acetone and various alkyl and aryl halides via dichlorohydrins followed by cyclization. The reactive 2-substituted epichlorohydrins were subjected to nucleophilic attacking of azide and cyanide ions to afford corresponding β-azido alcohols and α,β-unsaturated nitriles.

A novel effective transition metal based salt-catalyzed azidolysis of 1,2-epoxides

A simple, efficient, stereoselective, and in some cases usefully non-regioselective method for the synthesis of β-azido alcohols by the direct opening of 1,2-epoxides with 1,1,3,3-tetramethylguanidinium azide (TMGA) in CH 3CN, catalyzed by simple transition metal-based salts [Hf(OTf) 4, Zr(OTf) 4, Yb(OTf) 3], is described. Also TMSN 3 may be used in some reactions as a source of N 3−. This new method appears to be competitive with other methods previously reported.

Meso Epoxides in Asymmetric Synthesis: Enantioselective Opening by Nucleophiles in the Presence of Chiral Lewis Acids

The metal center coordinates to the epoxide oxygen atom, and the chiral ligand environment enables a nucleophile to discriminate between the formally enantiotopic carbon–oxygen bonds. The method developed by W. A. Nugent functions along this principle: the reaction of a range of meso epoxides with tri-alkylsilyl azides can be catalyzed by a new chiral Lewis acid derived from zirconium and gives β-azido alcohols in very good enantiomeric excesses. Nu = N3, R1R2 = CH3, (CH2)4, etc.

ChemInform Abstract: SYNTHESIS OF 2‐ETHYNYLAZIRIDINES

AbstractDie aus den acetylensubstituierten Epoxiden (I) durch Umsetzung mit primären Aminen (II) gebildeten Aminoalkohole (III) bzw. (V) cyclisieren unter der Einwirkung von Triphenylphosphin oder Triethylamin zu Ethinylaziridinen (IV).

Synthesis of 2-ethynylaziridines

2-Ethynyl-substituted aziridines were obtained by the reaction of acetylenic β-amino and β-azido alcohols with triphenylphosphine and carbon tetrachloride in the presence of triethylamine. The cycloaddition of carbenes and diazomethane to an acetylenic imine was investigated. 2-Ethynylaziridines were obtained in the case of carbonylalkoxycarbenes. The regioselectivity of the cycloaddition of carbenes to an acetylenic imine is demonstrated.