- Fenton-Inspired C-H Functionalization: Peroxide-Directed C-H Thioetherification
-
Substoichiometric iron mediates the thioetherification of unactivated aliphatic C-H bonds directed by resident silylperoxides. Upon exposure to a catalytic amount of iron(II) triflate, TIPS-protected peroxides bearing primary, secondary, and tertiary C-H sites undergo chemoselective thioetherification of remote C-H bonds with diaryl disulfides. The reaction demonstrates a broad substrate scope and functional group tolerance without the use of any noble metal additives. Mechanistic experiments suggest that the reaction proceeds through 1,5-H atom abstraction by a hydroxyl radical generated with iron.
- Groendyke, Brian J.,Modak, Atanu,Cook, Silas P.
-
p. 13073 - 13091
(2019/10/10)
-
- DIHYDROPYRONE COMPOUNDS AND HERBICIDES COMPRISING THE SAME
-
The present invention provides a compound having an excellent efficacy for controlling weeds. A dihydropyrone compound of formula (I): wherein m is 1, 2 or 3; n is an integer of any one of 1 to 5; X represents O, S, S(O) or S(O)2; R1 /sup
- -
-
Paragraph 0125
(2014/06/23)
-
- Grignard reagents: Alkoxide-directed iodine-magnesium exchange at sp 3 centers
-
(Chemical Equation Presented) Sequential addition of i-PrMgCl and BuLi to sp3 hybridized iodoalcohols triggers a facile iodine-metal exchange. Intercepting the resulting cyclic Grignard reagents with a slight excess of an electrophile leads to a diverse range of substituted alcohols. The iodine-magnesium exchange strategy is effective with 3-carbon iodoalcohols bearing alkyl substitutents on the carbinol or adjacent carbons and with the chain-extended homolog 4-iodobutan-1-ol.
- Fleming, Fraser F.,Gudipati, Subrahmanyam,Vu, Viet Anh,Mycka, Robert J.,Knochel, Paul
-
p. 4507 - 4509
(2008/03/11)
-
- Sulfone derivatives as 5-HT7 receptor ligands
-
The present invention relates to sulfone derivatives of formula (I): Ar—SO2—CR2R3-L-N(R1)2??I wherein Ar, L, R1, R2 and R3 are as defined herein, and pharmaceutically
- -
-
Page/Page column 8
(2010/02/09)
-
- Regioselective free radical phenylsulfenation of a non-activated δ-carbon atom by the photolysis of alkyl benzenesulfenate
-
A regioselective free radical introduction of a phenylthio group onto a non-activated δ-carbon atom was achieved by photolysis of alkyl benzenesulfenates in the presence of hexabutylditin, and δ-phenylthio alcohols were obtained in 35-91% yields. δ-Phenyl
- Petrovi?, Goran,Sai?i?, Radomir N.,?ekovi?, ?ivorad
-
p. 187 - 196
(2007/10/03)
-
- Formation of cyclic sulfonium salts by Me3SiI-promoted intramolecular displacement of hydroxide or methoxide by sulfide. Ring contraction thiepane → thiolane
-
A suitably positioned (1,2-, 1,4-, and 1,5-) intramolecular sulfide interferes with the iodotrimethylsilane-promoted iodine for hydroxyl substitution, as well as the related alcohol deprotection procedure (regioselective cleavage of methyl ethers). The ou
- Cere, Vanda,Pollicino, Salvatore,Fava, Antonino
-
p. 5989 - 5998
(2007/10/03)
-
- Benzophenone Dicarboxylic Acid Antagonists of Leukotriene B4. 2. Structure-Activity Relationships of the Lipophilic Side Chain
-
A series of lipophilic benzophenone dicarboxylic acid derivatives were found to inhibit the binding of the potent chemotoxin leukotriene B4 (LTB4) to its receptor on intact human neutrophils.Activity at the LTB4 receptor was determined by using a 3H>LTB4-binding assay.The structure-activity relationship for the lipophilic side chain was systematically investigated.Compounds with n-alkyl side chains of varying lengths were prepared and tested.Best inhibition of 3H>LTB4 binding was observed with the n-decyl derivative.Analogues with alkyl chains terminated with an aromatic ring showed improved activity.The 6-phenylhexyl side chain was optimal.Substitution on the terminal aromatic ring was also evaluated.Methoxyl, methylsulfinyl, and methyl substituents greatly enhanced the activity of the compound.For a given substituent, the para isomer had the best activity.Thus the nature of the lipophilic side chain can greatly influence the ability of the compounds to inhibit the binding of LTB4 to its receptor on intact human neutrophils.The most active compound from this series, 84 (LY223982), bound to the LTB4 receptor with the affinity approaching that of the agonist.
- Gapinski, D. Mark,Mallett, Barbara E.,Froelich, Larry L.,Jackson, William T.
-
p. 2807 - 2813
(2007/10/02)
-
- A FACILE SYNTHESIS OF SPIROKETALS
-
A convenient synthetic approach to spiroketals based on the addition of α-sulfonylcarbanions to lactones is described.
- Brimble, Margaret A.,Officer, David L.,Williams Geoffrey M.
-
p. 3609 - 3612
(2007/10/02)
-
- Elimination and Addition Reactions. Part 44. Eliminative Fission of Cycloalkanols
-
Activation parameters for the fission of cyclopropanols and cyclobutanols with phenyl groups α or phenylthio or phenylsulphonyl groups β to the hydroxy group have been obtained.The results show very large differences in reactivity between cyclopropanols and cyclobutanols; such differences are also found in energy profiles for the opening of cycloalkoxide ions obtained by using MINDO3.The results are entirely compatible with other three-membered/four-membered ring comparisons and the role of strain in these systems is discussed.Attempts to extend the well established enforced catalysis of cycloalkanol ring fission to electrophiles other than Broensted acids have failed.
- Bury, Adrian,Earl, Harold A.,Stirling, Charles J. M.
-
p. 1281 - 1288
(2007/10/02)
-
- APPROACHES TO THE SYNTHESIS OF ASPIDOSPERMA ALKALOIDS. PART II. THE SYNTHESIS OF 18,19-DIDEHYDROTABERSONINE.
-
The total synthesis of 18,19-dehydrotabersonine, via 3-oxo-18,19-didehydrovincadifformine, is described.
- Blowers, John W.,Saxton, J. Edwin,Swanson, Alistair G.
-
p. 6071 - 6095
(2007/10/02)
-
- N-(arylthioalkyl)-N'-(aminoalkyl)ureas
-
N-(arylthioalkyl)-N'-(aminoalkyl)ureas and thioureas and oxidation derivatives having the formula STR1 wherein B is thio, sulfinyl or sulfonyl; R1 and R2 are hydrogen, loweralkyl, cycloalkyl, 2-furanyl, phenyl, substituted phenyl or phenyl-loweralkyl and R3 and R4 are hydrogen, loweralkyl, phenyl or phenyl-loweralkyl wherein phenyl is optionally substituted, or R3 and R4 taken with the adjacent nitrogen form a heterocyclic residue.
- -
-
-
- A NEW SYNTHESIS OF α,β-UNSATURATED γ- AND δ-LACTONS VIA INTRAMOLECULAR ACYLATION OF α-SULFINYL CARBANION
-
A new synthesis of α,β-unsaturated γ- and δ-lactones involving the intramolecular acylation of α-sulfinyl carbanion followed by pyrolisis is described.
- Pohmakotr, Manat,Jarupan, Prapanpong
-
p. 2253 - 2256
(2007/10/02)
-
- γ- and δ-epoxy sulfones. Formation of different ring-sized products upon reaction with CH3MgI or LiN2
-
γ-Epoxy sulfones in which the epoxide function is terminal yield cyclopropylmethanol derivatives on reaction with methylithium or lithium diisopropylamide.In contrast, treatment of these epoxides with two equivalents of CH3MgI gives only cis-3-phenylsulfonylcyclobutanols.The cis-relationship between the OH and sulfonyl groups was proven in one instance by an X-ray stucture determination.Inernal γ-epoxy sulfones yield cyclopropylmethanols with all bases studied.All δ-epoxy sulfones studied furnished cis-3-phenylsulfonylcyclopentanols upon reaction with the Grignard reagent.These same epoxides gave either cyclopentanols or noncyclic products upon reaction with LDA; no cyclobutane ring containing products were obtained contrary to the expectations based on Stork's results with the corresponding epoxy nitriles (ref. 2).The mechanism of the Grignard-mediated reaction involves epoxide opening by iodide ion, α-sulfonyl Grignard formation, and, finally, cyclization.When LDA or CH3Li is used the products are formed by an intramolecular SN2 opening of the epoxide by an α-lithio sulfone.
- Decesare, John M.,Corbel, Bernard,Durst, Tony,Blount, John F.
-
p. 1415 - 1424
(2007/10/02)
-