Davis Reagent Research Articles

ChemInform Abstract: Enantioselective Synthesis of the ABC‐Tricyclic Core of Phomactin A by a γ‐Hydroxylation Strategy.

An enantioselective synthesis of the ABC-tricyclic furanochroman core of phomactin A has been accomplished by a γ-hydroxylation approach. The C ring was established by γ-hydroxylation of an α-enone. The regioselectivity was optimized by using a strong base with an oxophilic cation (t-BuLi) and a bulky oxygen donor (Davis reagent), which afforded the γ-hydroxylation product selectively in 63% yield.

Enantioselective Synthesis of the ABC-Tricyclic Core of Phomactin A by a γ-Hydroxylation Strategy

An enantioselective synthesis of the ABC-tricyclic furanochroman core of phomactin A has been accomplished by a γ-hydroxylation approach. The C ring was established by γ-hydroxylation of an α-enone. The regioselectivity was optimized by using a strong base with an oxophilic cation (t-BuLi) and a bulky oxygen donor (Davis reagent), which afforded the γ-hydroxylation product selectively in 63% yield.

2-(Phenylsulfonyl)-3-phenyl-oxaziridine (Davis Reagent)

2-(Phenylsulfonyl)-3-phenyl-oxaziridine (Davis Reagent)

Protecting-group-free catalytic asymmetric total synthesis of (−)-rosmarinecine

The protecting-group-free asymmetric total synthesis of (−)-rosmarinecine was achieved in only four steps from the commercially available (±)-3-hydroxypyrrolidine hydrochloride (2a). The key steps include the direct oxidation of (±)-2a to (±)-3-hydroxy-1-pyrroline N-oxide (1a) using the Davis reagent and the domino reaction; viz., the lipase-catalyzed dynamic kinetic resolution of (±)-1a with 1-ethoxyvinyl ethyl maleate followed by the intramolecular [3+2] dipolar cycloaddition reaction of the generated optically active ester. Some insights into the mechanism of the racemization of the optically active 1a, observed during the enzymatic process, were also obtained.

Generation of Stereocenters Around a C3-Symmetric Cyclotriveratrylene Crown

The oxidation of racemic methylthio-substituted C3-symmetric cyclotriveratrylene (CTV) 2 produces the corresponding trisulfoxides 3 as follows. Oxidation with m-chloroperoxybenzoic acid (m-CPBA) in dichloromethane leads to the formation of a distribution of the four possible diastereomers that is relatively close to the statistical outcome, in which the C3-symmetric stereoisomers are the minor species. In contrast, the optically active Davis reagent [oxaziridine (+)-4] in carbon tetrachloride at room temperature leads to a biased (73 %) distribution in favor of the C3-symmetric MRRR/PSSS diastereomer of 3 with 56 % ee (PSSS enantiomer according to the model of Davis). Interestingly, when the oxidation is carried out in toluene at reflux, the distribution is switched to approximately equal amounts of the C3-symmetric MSSS/PRRR and asymmetric MRSS/PSRR diastereomers of 3. Overall, however, these results point to the negligible role played by the chirality of the CTV platform on the induction of chirality at the sulfur prochiral centers.

ChemInform Abstract: A New Reaction of 2-(Phenylsulfonyl)-3-phenyloxaziridine (Davis Reagent): Oxidation of Thiolates to Sulfinates. Application to the Synthesis of Sulfones.

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.

Preparation of New tert-Butyl Substituted Coumarins, Thiocoumarins and Dithiocoumarins

6-tert-Butyl-4-methyl- and 6,8-di-tert-butyl-4-methylcoumarin were prepared from tert-butylphenols and diketene via the corresponding aryl acetoacetates. 6-tert-Butyl-4-methyl-thiocoumarin ( 6 ) was obtained from 6-tert-butylthiophenol. Thionation with Lawesson's or Davy's reagent led to the related thion- and dithiocoumarins. The structures were proved by NMR spectroscopy and an X-ray structure analysis of 6.

Synthesis and thermal stability of S‐trimethylsilyl esters of tetracoordinated phosphorus amidothioacids

AbstractS‐(Diethylamino)dimethylsilyl bis(diethylamido)dithiophosphate 3 was obtained by the reaction of tetraphosphorus decasulfide 1 with bis(diethylamino)dimethylsilane 2a. The reactions of Lawesson's reagent 5 with 2a and the alkyl homologues of Davy's reagent 8a,b with trimethyl(diethylamino)silane 6 were studied. On the basis of these reactions, methods of synthesizing S‐(diethylamino)dimethylsilyl or S‐(diethylamino)diphenylsilyl 4‐methoxyphenyl (diethylamido)dithiophosphonates 7a and 7b and S‐trimethylsilyl S‐alkyl(diethylamido)trithiophosphates 9a,b are described. The optimal reaction conditions and thermal stability of S‐trimethylsilyl S‐ethyl(diethylamido)trithiophosphate 9a were defined by differential thermal analyses. Compound 9a have been decomposed to form 2,4‐bis(diethylamido)‐1,3,2,4‐dithiadiphosphetane‐2,4‐disulfide 10 which structure was established by X‐ray single crystal diffraction. © 2006 Wiley Periodicals, Inc. Heteroatom Chem 17:670–675, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20231

Synthesis of (2R,3aR,8aR)‐6‐Chloro‐3a‐hydroxy‐l,2,3,3a,8,8a‐hexahydropyrrolo[2,3‐b]indole‐2‐carboxylic Acid Methyl Ester by Reductive Cyclization

AbstractA synthesis of (2R,3aR,8aR)‐6‐chloro‐3a‐hydroxy‐1,2,3a8,8a‐hexahydropyrrolo[2,3‐b]indole‐2‐carboxylic acid methyl ester (1) was achieved. An aldol reaction with Garner aldehyde, a hydroxyl introduction by Davis reagent, and a reductive intramolecular ring‐closure reaction were served as the key steps. This piece of work provides a new way to synthesize the analogues of hexahydropyrrolo[2,3‐b]indole, starting from readily available chemical substrates and inexpensive reagents.

Development of a Safe and Scalable Amine-to-Nitrone Oxidation: A Key Step in the Synthesis of R107500

The stepwise optimization towards a safe, reproducible, and high-yielding oxidation of azepine 2 into the prochiral nitrone 4 is described, with emphasis on the elimination of Davis reagent 3. m-Chloroperoxybenzoic acid (mCPBA) was found to be an elegant and scalable alternative oxidant regarding safety, yield, and easy workup procedures. Nitrone 4 was obtained in 95% yield and used without purification or isolation in the cycloaddition step to provide oxazolidone 6 in high yield. The process was scaled up successfully to an 800-L scale (60 mol of starting material).

Asymmetric synthesis of a neuroprotective and orally active N-methyl- d-aspartate receptor ion-channel blocker, CNS 5788

Asymmetric synthesis of N-(2-chloro-5-methylthiophenyl)- N′-(3-methylsulfinylphenyl)- N′-methylguanidine (CNS 5788) was achieved in high enantiomeric excess through condensation of the cyanamide derivative, 6 and the sulfinylaniline hydrochloride, 5. The key step involved the asymmetric oxidation of N-methyl-3-methylthioaniline using a Davis reagent.

A New Reaction of 2-(Phenylsulfonyl)-3-phenyloxaziridine (Davis Reagent): Oxidation of Thiolates to Sulfinates. Application to the Synthesis of Sulfones

The first efficient and general method for the generation of sulfinate anions by oxidation of the corresponding thiolates is described. The oxidizing agent employed is the classical 2-(phenylsulfonyl)-3-phenyloxaziridine, commonly known as the Davis reagent. Subsequent S-alkylation of the sulfinates under phase-transfer catalysis affords sulfones 6 in 71−91% isolated yields (10 examples).

Total synthesis of (+/-)-methyl rishirilide B.

[formula: see text] A regio- and stereospecific total synthesis of (+/-)-methyl rishirilide B (2b), and (alpha)2-macroglobulin inhibitor, is described. A key feature of the synthetic plan was regiospecific construction of a hydroanthracenone intermediate through condensation of a phenylsulfonyl isobenzofuranone with a functionalized 2-cyclohexen-1-one. Introduction of the vicinal trans-hydroxyl groups in the densely functionalized A-ring was accomplished via a novel one-pot procedure that involved oxidation of enolate anions with the Davis reagent.

Reactions of dithioxo‐1,3,2λ5,4λ5‐dithiadiphosphetanes with antimony(III) alkoxides

New antimony(III) derivatives of dithiophosphonic and trithiophosphoric acids 3a–c and 5 were obtained by the reactions of Lawesson's reagent 1a, its homologue 1b, and the isobutyl homologue of Davy's reagent 4 with antimony(III) alkoxides 2a–c. © 1999 John Wiley & Sons, Inc. Heteroatom Chem 10: 399–403, 1999

INFLUENCE OF NUCLEOPHILIC REAGENTS ON THE REACTIONS OF PHOSPHORUS SULFIDES AND ALKYL HOMOLOGUES OF DAVY'S REAGENT WITH ALKYL HALIDES AND DIALKYL DISULFIDES

Use of potassium carbonate, sodium sulfide and sodium alkylthiolates results in the reactivity enhancement of phosphorus sulfides (P4S10, P4S7 and P4S5) and alkyl homologues of Davy's reagent in their reactions with alkyl halides and dialkyl disulfides.

Practical methods for the preparation of spiro[benzo[ c]thiophene-1(3 H),4′-piperidine]-(2 S)-oxide by resolution and asymmetric sulfoxidation

We report simple and efficient methods for the preparation of enantiomerically pure spiro[benzo[ c]thiophene-1(3 H),4′-piperidine]-(2 S)-oxide ( S)- 1, a key intermediate for the synthesis of tachykinin receptor antagonist, by resolution and asymmetric sulfoxidation. Racemic ( RS)- 1 can be resolved with ( S)-(+)-mandelic acid in acetonitrile to give ( S)- 1 of >99% ee. We also describe the asymmetric sulfoxidation of sulfide 5 in excellent enantiomeric excess and high chemical yield by the use of the Davis reagent.

INFLUENCE OF NUCLEOPHILIC REAGENTS ON THE REACTIONS OF PHOSPHORUS SULFIDES AND ALKYL HOMOLOGUES OF DAVY'S REAGENT WITH ALKYL HALIDES AND DIALKYL DISULFIDES

Use of potassium carbonate, sodium sulfide and sodium alkylthiolates results in the reactivity enhancement of phosphorus sulfides (P4S10, P4S7 and P4S5) and alkyl homologues of Davy's reagent in their reactions with alkyl halides and dialkyl disulfides.

An Anomalous Reaction of 2-Benzenesulfonyl-3-aryloxaziridines (Davis Reagents) with Indoles: Evidence for a Stepwise Reaction of the Davis Reagent with a π-Bond

ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTAn Anomalous Reaction of 2-Benzenesulfonyl-3-aryloxaziridines (Davis Reagents) with Indoles: Evidence for a Stepwise Reaction of the Davis Reagent with a π-BondSalim Mithani, David M. Drew, Edwin H. Rydberg, Nicholas J. Taylor, Sandra Mooibroek, and Gary I. DmitrienkoView Author Information Department of Chemistry Guelph-Waterloo Centre for Graduate Work in Chemistry Waterloo Campus, University of Waterloo Waterloo, Ontario, Canada N2L 3G1 Cite this: J. Am. Chem. Soc. 1997, 119, 5, 1159–1160Publication Date (Web):February 5, 1997Publication History Received9 September 1996Published online5 February 1997Published inissue 1 February 1997https://doi.org/10.1021/ja963159dCopyright © 1997 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views1000Altmetric-Citations48LEARN 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 Read OnlinePDF (202 KB) Get e-AlertsSupporting Info (2)»Supporting Information Supporting Information SUBJECTS:Adducts,Chemical reactions,Ethers,Indoles,Reagents Get e-Alerts

Influence of Iodine on Reactivity of Phosphorus Sulfides and Homologues of Davy's Reagent in Organic Reactions

Abstract The use of iodine results in reactivity enhancement of phosphorus sulfides and homologues of Davy's reagent in the reactions with disulfides, aminals and thioacetals. The reactions β-diiodotetraphosphorus trisulfides with disulfides, aminals and thioacetals were studied.

Synthesis of Thione Analogues of Monobactams

AbstractOptically active β‐lactams 4 were treated with Lawesson's reagent (2) or Davy's reagent (3) to give the β‐thiolactams 5. Demethylation of 5 by reduction with dissolved metal gave the 1‐unsubstituted 2‐azetidinethiones 6 which were sulfonated and Boc‐deprotected to provide (3S)‐amino‐2‐thiomonobactamic acids 8. The side chain on nitrogen was introduced by using 1‐hydroxybenzotriazole‐activated acids 9. Deprotection of functional groups in the side chain yielded the β‐thiolactam analogues 11a, 11b of SQ 81,377 and aztreonam (1). These compounds were found to be weakly active against a range of Gram‐negative bacteria.