5925-86-0Relevant academic research and scientific papers
Synthesis of dibenzo[c,e]oxepin-5(7H)-ones from benzyl thioethers and carboxylic acids: Rhodium-catalyzed double C-H activation controlled by different directing groups
Zhang, Xi-Sha,Zhang, Yun-Fei,Li, Zhao-Wei,Luo, Fei-Xian,Shi, Zhang-Jie
supporting information, p. 5478 - 5482 (2015/04/27)
A rhodium(III)-catalyzed cross-coupling of benzyl thioethers and aryl carboxylic acids through the two directing groups is reported. Useful structures with diverse substituents were efficiently synthesized in one step with the cleavage of four bonds (C-H, C-S, O-H) and the formation of two bonds (C-C, C-O). The formed structure is the privileged core in natural products and bioactive molecules. This work highlights the power of using two different directing groups to enhance the selectivity of a double C-H activation, the first of such examples in cross-oxidative coupling.
Photoinduced One-Electron Oxidation of Benzyl Methyl Sulfides in Acetonitrile: Time-Resolved Spectroscopic Evidence for a Thionium Ion Intermediate
Bettoni, Marta,Del Giacco, Tiziana,Stradiotto, Marina,Elisei, Fausto
, p. 8001 - 8008 (2015/09/01)
The photo-oxidation of 4-methoxybenzyl methyl sulfide (1a), benzyl methyl sulfide (1b), and 4-cyanobenzyl methyl sulfide (1c) has been investigated in the presence of N-methoxy phenanthridinium hexafluorophosphate (MeOP+PF6-) under nitrogen in CH3CN. The steady-state photolysis experiments showed for the investigated sulfides exclusively the formation of the corresponding benzaldehyde as the oxidation product, reasonably due to a deprotonation of the sulfide radical cations. Photo-oxidation of 1a-1c occurs through an electron transfer process. Indeed, laser flash photolysis measurements showed an efficient formation of sulfide radical cations, detected in their dimeric form [(4-X-C6H4CH2SCH3)2+] at ≈520 nm. At longer delay times, the absorption of the dimer radical cation was replaced by an absorption band assigned to the (α-thio)benzyl cation (thionium ion, γmax = 420-400 nm), formed by oxidation of the benzyl radical and not by that of the (α-thiomethyl)benzyl radical, as expected if a Cα-H bond cleavage is operative. This finding highlights a particular stability of this kind of cation never reported before, even though its involvement in one-electron oxidation mechanisms of various sulfides has already been invoked. Density functional theory calculations allowed identification of a significant charge and spin delocalization involving both the phenyl ring and the sulfur atom of the radical cations.
Thioethers as directing group for the palladium-catalyzed direct arylation of arenes
Yao, Jinzhong,Yu, Ming,Zhang, Yuhong
supporting information, p. 3205 - 3210 (2013/01/15)
Thioethers have proven to be efficient directing groups for the arylation of arenes under palladium catalysis. The thioether group can be readily removed or converted to other functional groups. Kinetic isotopic effect studies reveal that the C-H cleavage of arenes might be the turnover-limiting step. Copyright
Enzyme-catalyzed transfer of a ketone group from an S-adenosylmethionine analogue: A tool for the functional analysis of methyltransferases
Lee, Bobby W. K.,Sun, He G.,Zang, Tianzhu,Ju-Kim, Byung,Alfaro, Joshua F.,Zhou, Zhaohui Sunny
supporting information; experimental part, p. 3642 - 3643 (2010/05/15)
"Chemical equation presented" S-Adenosylmethionine (AdoMet or SAM)-dependent methyltransferases belong to a large and diverse family of group-transfer enzymes that perform vital biological functions on a host of substrates. Despite the progress in genomics, structural proteomics, and computational biology, functional annotation of methyltransferases remains a challenge. Herein, we report the synthesis and activity of a new AdoMet analogue functionalized with a ketone group. Using catechol O-methyltransferase (COMT, EC 2.1.1.6) and thiopurine S-methyltransferase (TPMT, EC 2.1.1.67) as model enzymes, this robust and readily accessible analogue displays kinetic parameters that are comparable to AdoMet and exhibits multiple turnovers with enzyme. More importantly, this AdoMet surrogate displays the same substrate specificity as the natural methyl donor. Incorporation of the ketone group allows for subsequent modification via bio-orthogonal labeling strategies and sensitive detection of the tagged ketone prod cts. Hence, this AdoMet analogue expands the toolbox available to interrogate the biochemical functions of methyltransferases.
Azetidine derivatives, their preparation and medicaments containing them
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, (2008/06/13)
The invention concerns compounds of formula (1) wherein: R represents a chain (A) or (B); R1 is methyl or ethyl; R2 is either an optionally substituted aromatic or an optionally substituted heteroaromatic ring; R3 and R4, identical or different, are either an optionally substituted aromatic or an optionally substituted heteroaromatic ring; R′ represents a hydrogen atom or a —CO—alk radical, their optical isomers, their salts, their preparation and medicines containing them.
BIOTRANSFORMATION OF ORGANIC SULFIDES. PART 6. FORMATION OF CHIRAL para-SUBSTITUTED BENZYL METHYL SULFOXIDES BY HELMINTHOSPORIUM SPECIES NRRL 4671
Holland, Herbert L.,Brown, Frances M.,Larsen, Brett G.
, p. 1561 - 1568 (2007/10/02)
The fungus Helminthosporium species NRRL 4671 has been used for the biotransformation of a series of para-substituted benzyl sulfides with substituent groups consisting of trifluoromethyl, halo, hydroxy, methoxy, acetoxy, nitro, cyano, amino, acetamido, acyl and carboxylic acid units.In all cases, sulfoxide formation occurred in good yoeld and with predominant (S) chirality at the sulfur position.A minor amount of sulfone product was also obtained from the halo- and methoxy-substituted substrates.
Electrophilic Methylthiomethylation of Enol Ethers and Activated Aromatic Compounds. Application of the Former Reaction to the Synthesis of the Macrocycle, 3,3,7,7,11,11,15,15-Octamethyl-1,9-dithia-5,13-diazacyclohexadecane
McCrindle, Robert,McAlees, Alan J.,Stephenson, Donald K.
, p. 3070 - 3073 (2007/10/02)
Enol ethers of dialkylacetaldehydes, either as such, or generated in situ from the corresponding acetals, undergo ready methylthiomethylation when heated with dimethyl sulphoxide-acetic anhydride (or methylthiomethyl acetate) in the presence of boron trifluoride-diethyl ether.These same reagent combinations can be used to methylthiomethylate certain activated aromatic compounds.The synthetic utility of the former reaction is demonstrated in the synthesis of 2,2,6,6-dimethyl-4-thiaheptanedial (4) which has been converted into 3,3,7,7,11,11,15,15-octamethyl-1,9-dithia-5,13-diazacyclohexadecane (7).
