نتایج جستجو برای: sulfoxides

تعداد نتایج: 3344  

Journal: :Organic & biomolecular chemistry 2013
Stuart G Collins Orlagh C M O'Sullivan Patrick G Kelleher Anita R Maguire

Diazo transfer adjacent to a sulfoxide moiety to provide stable, isolable α-diazo-β-oxo sulfoxides has been achieved. Use of monocyclic and bicyclic sulfoxide precursors is critical in enabling isolation of stable derivatives, through introduction of conformational constraint, while acyclic α-diazo-β-oxo sulfoxides are too labile to isolate and characterize.

Journal: :Chemical communications 2016
José A Fernández-Salas Alexander P Pulis David J Procter

Metal-free C-H thioarylation of arenes and heteroarenes using methyl sulfoxides constitutes a general protocol for the synthesis of high value diaryl sulfides. The coupling of arenes and heteroarenes with in situ activated sulfoxides is regioselective, uses readily available starting materials, is operationally simple, and tolerates a wide range of functional groups.

2018
Mindaugas Šiaučiulis Selma Sapmaz Alexander P. Pulis David J. Procter

A dual vicinal functionalisation cascade involving the union of heterocycles and allyl sulfoxides is described. In particular, the approach provides efficient one-step access to biologically relevant and synthetically important C3 thio, C2 carbo substituted indoles. The reaction operates under mild, metal free conditions and without directing groups, via an interrupted Pummerer coupling of acti...

1999
Giulia Licini Marcella Bonchio Giorgio Modena William A. Nugent

Monomeric Ti(IV)/C3 trialkanolamine complexes are effective catalysts in the stereoselective sulfoxidation of alkyl aryl sulfides (ee’s up to 84%, 0.1% of catalyst). Such complexes were shown to have a biphilic nature, behaving as electrophilic oxidants towards sulfides while a nucleophilic pathway dominates the oxidation of sulfoxides. The analogous Zr(IV) complexes, likely dimeric, are even b...

Journal: :Organic & biomolecular chemistry 2014
Peter J Rayner Giacomo Gelardi Peter O'Brien Richard A J Horan David C Blakemore

A synthetic study on the preparation of N-Boc α-amino sulfoxides has revealed an unexpected instability which is believed to be due to α-elimination of the sulfoxide to give an iminium ion. Full synthetic details are reported on two main synthetic routes: lithiation and sulfinate trapping of N-Boc heterocycles and oxidation of N-Boc α-amino sulfides. Six novel α-amino sulfoxides were successful...

2012
Martin A Fascione Sophie J Adshead Pintu K Mandal Colin A Kilner Andrew G Leach W Bruce Turnbull

Sulfoxides are frequently used in organic synthesis as chiral auxiliaries and reagents to mediate a wide variety of chemical transformations. For example, diphenyl sulfoxide and triflic anhydride can be used to activate a wide range of glycosyl donors including hemiacetals, glycals and thioglycosides. In this way, an alcohol, enol or sulfide is converted into a good leaving group for subsequent...

Journal: :Phosphorus Sulfur and Silicon and The Related Elements 2022

Difluoroenol silyl ethers are a unique class of enol that widely used as powerful difluoroalkylating reagent to incorporate difluoromethylene groups into organic molecules. In this context, we revealed fluorine effect the difluoroenol exhibit oxygen nucleophilicity in lieu traditional α-carbon toward aromatic iodonium/sulfonium species, thus allowing us develop difluoroalkylative [3,3]-rearrang...

2017
Adesh Kumar Singh Varsha Tiwari Kunj Bihari Mishra Surabhi Gupta Jeyakumar Kandasamy

A practical method for the selective and controlled oxidation of thioglycosides to corresponding glycosyl sulfoxides and sulfones is reported using urea-hydrogen peroxide (UHP). A wide range of glycosyl sulfoxides are selectively achieved using 1.5 equiv of UHP at 60 °C while corresponding sulfones are achieved using 2.5 equiv of UHP at 80 °C in acetic acid. Remarkably, oxidation susceptible ol...

2017
Anthonius H. J. Engwerda Niels Koning Paul Tinnemans Hugo Meekes F. Matthias Bickelhaupt Floris P. J. T. Rutjes Elias Vlieg

Despite the importance of enantiopure chiral sulfoxides, few methods exist that allow for their deracemization. Here, we show that an enantiopure sulfoxide can be produced from the corresponding racemate using Viedma ripening involving rearrangement-induced racemization. The suitable candidate for Viedma ripening was identified from a library of 24 chiral sulfoxides through X-ray structure dete...

Journal: :Organic & biomolecular chemistry 2012
Derek R Boyd Narain D Sharma Brian McMurray Simon A Haughey Christopher C R Allen John T G Hamilton W Colin McRoberts Rory A More O'Ferrall Jasmina Nikodinovic-Runic Lydie A Coulombel Kevin E O'Connor

Asymmetric heteroatom oxidation of benzo[b]thiophenes to yield the corresponding sulfoxides was catalysed by toluene dioxygenase (TDO), naphthalene dioxygenase (NDO) and styrene monooxygenase (SMO) enzymes present in P. putida mutant and E. coli recombinant whole cells. TDO-catalysed oxidation yielded the relatively unstable benzo[b]thiophene sulfoxide; its dimerization, followed by dehydrogena...

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