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Search for "thioethers" in Full Text gives 64 result(s) in Beilstein Journal of Organic Chemistry.
Fluorine-containing substituents: metabolism of the α,α-difluoroethyl thioether motif
Beilstein J. Org. Chem. 2019, 15, 1441–1447, doi:10.3762/bjoc.15.144
- reduces relative to the perfluoro substituents [13][14][15]. In this context we recently introduced aryl α,α-difluoroethyl thioethers such as 1 as a motif of this class [16][17][18]. Log P assessments of PhSCF2CH3 (1) indicate that it is more polar than the PhSCF3 (2) and also the aliphatic PhSCH2CH3
- context, the potential for P450 oxidation at sulphur is the most obvious metabolic vulnerability, and also hydrolytic susceptibility to release fluoride. We chose to explore the metabolism of aryl α,α-difluoroethyl thioethers 4 and 5 by Cunninghamella elegans as representative compounds of this class
- . This fungus is rich in cytochrome P450 activity and has been used as a model organism in which to mimic phase one mammalian metabolism of xenobiotics [19][20][21]. Results and Discussion The two aryl α,α-difluoroethyl thioethers 4 and 5 in Figure 3 were selected for C. elegans incubations rather than 1
Applications of organocatalysed visible-light photoredox reactions for medicinal chemistry
Beilstein J. Org. Chem. 2018, 14, 2035–2064, doi:10.3762/bjoc.14.179
- the formation of aromatic thioethers by functionalising C–H bonds of imidazo[1,2-α]pyridines and benzo[d]imidazo[1,2-b]thiophenes using Eosin B and sulfinic acids (Scheme 8) [51]. The manipulated heterocycles, particularly the imidazopyridines, are motifs which are commonly encountered in medicinal
Water-soluble SNS cationic palladium(II) complexes and their Suzuki–Miyaura cross-coupling reactions in aqueous medium
Beilstein J. Org. Chem. 2018, 14, 1859–1870, doi:10.3762/bjoc.14.160
- reactions [32][33]. As it was elegantly reviewed by Singh and co-workers [33], these organosulfur ligands can be classified into pincer type (symmetrical and unsymmetrical), thioethers, thiourea-based ligands, sulfur-substituted NHCs, thiosemicarbazones and sulfated Schiff bases. Of the pincer ligands
β-Hydroxy sulfides and their syntheses
Beilstein J. Org. Chem. 2018, 14, 1668–1692, doi:10.3762/bjoc.14.143
- group from succinimide 103 to the chiral pre-catalyst 104 to generate the active species 110 (Scheme 40). Reaction of the alkene with the active species 110 results to the formation of the thiiranium intermediate 111, which then undergoes a stereoselective nucleophilic addition to provide the thioethers
Atom-economical group-transfer reactions with hypervalent iodine compounds
Beilstein J. Org. Chem. 2018, 14, 1263–1280, doi:10.3762/bjoc.14.108
- economy for this transformation is rather low (26% for Ar = Ph). However, 45% of the molecular weight of the starting iodonium salt 1 is present in the product 3’. Diaryl thioethers 5 can be synthesized using either cyclic iodonium salts (will be discussed briefly in section 1.2) or their acyclic
- counterparts 1 (Scheme 4) [26][27]. Jiang and co-workers developed a Cu(II)-catalysed methodology for the conversion of acyclic diaryliodonium salts 1 and potassium thioacetate to the corresponding thioethers 5 (pathway (a)) and later applied the optimized reaction conditions towards cyclic iodonium salts. In
- of the corresponding λ3-iodane. (a) Structure of diaryliodonium salts 1. (b) Diarylation of a suitable substrate A with one equivalent of diaryliodonium salt 1. Synthesis of biphenyls 3 and 3’ with symmetrical diaryliodonium salts 1. Synthesis of diaryl thioethers 5. Synthesis of two distinct S-aryl
Mechanochemistry of nucleosides, nucleotides and related materials
Beilstein J. Org. Chem. 2018, 14, 955–970, doi:10.3762/bjoc.14.81
- chalogenate nucleophiles in a mixer ball mill using zirconia components [22]. Highly efficient transformations to the corresponding 4-methoxybenzyl thioethers were achieved in 15–60 minutes such that pure products could be isolated without the need for chromatography (Scheme 7). Of particular note was the
CF3SO2X (X = Na, Cl) as reagents for trifluoromethylation, trifluoromethylsulfenyl-, -sulfinyl- and -sulfonylation. Part 1: Use of CF3SO2Na
Beilstein J. Org. Chem. 2017, 13, 2764–2799, doi:10.3762/bjoc.13.272
Selective synthesis of thioethers in the presence of a transition-metal-free solid Lewis acid
Beilstein J. Org. Chem. 2016, 12, 2627–2635, doi:10.3762/bjoc.12.259
- Federica Santoro Matteo Mariani Federica Zaccheria Rinaldo Psaro Nicoletta Ravasio CNR ISTM, via C. Golgi 19, 20133 Milano, Italy 10.3762/bjoc.12.259 Abstract The synthesis of thioethers starting from alcohols and thiols in the presence of amorphous solid acid catalysts is reported. A silica
- substrates under mild reaction conditions. Keywords: no solvent; S-alkylation; solid acids; thioethers; transition-metal-free; Introduction The need for more sustainable processes in the fine chemical industry is growing continuously. An optimal use of resources, both energy and starting materials, and a
- are a very important field of research as traditional coupling methods, although they proved effective in industrial applications, generate harmful metal waste and many byproducts [3]. Thioethers are important building blocks for the synthesis of antibacterial and antifungal agents [4][5] and as
Cyclisation mechanisms in the biosynthesis of ribosomally synthesised and post-translationally modified peptides
Beilstein J. Org. Chem. 2016, 12, 1250–1268, doi:10.3762/bjoc.12.120
- only been described bioinformatically [123]. Subtilosin is a Bacillus RiPP antibiotic that belongs to the sactipeptide family of natural products that are defined by the presence of one or more sulphur to α-carbon bonds [125]. Three thioethers in subtilosin are formed by a single SPASM protein, AlbA
- -catalysed formation of thioethers in the biosynthesis of subtilosin. The mechanism for deoxyadenosine radical formation is consistent throughout most radical SAM enzymes. B) Mechanism of carbon–carbon cross-linking in streptide biosynthesis. C) Proposed carbon–carbon bond formation by SPASM protein PqqE in
Conjugate addition–enantioselective protonation reactions
Beilstein J. Org. Chem. 2016, 12, 1203–1228, doi:10.3762/bjoc.12.116
- , including alkyl, phenethyl, pendant esters and thioethers, and an α-acetyloxy group (81–98% yield, 95.5:4.5 to 97:3 er). Slightly lower enantioselectivity was observed only when R1 was benzyl (93.5:6.5 er). Methyl, ethyl, n-butyl, and isopentyl R2 substituted nitroalkenes were efficient substrates (84–98
1H-Imidazol-4(5H)-ones and thiazol-4(5H)-ones as emerging pronucleophiles in asymmetric catalysis
Beilstein J. Org. Chem. 2016, 12, 918–936, doi:10.3762/bjoc.12.90
- -addition to allenoates, which after elaboration of the resulting adducts, affords tertiary thioethers and alcohols [36] (Scheme 15). Starting from readily available L-valine and L-threonine the authors first synthesized different phosphine catalysts and then screened in the γ-addition reaction of both
- -catalyzed allylation substitution reaction of oxazol-4(5H)-ones and thiazol-4(5H)-ones to afford enantioenriched tertiary alcohols and thioethers (Scheme 19) [42]. In this case the diastereoselectivity is controlled by cations, in contrast to most of the described protocols wherein it is modulated by anions
- and to tertiary thiols and thioethers in the case of thiazolones. In the future, other Brønsted base or bifunctional catalyst promoted reactions with these compounds can be envisaged. Some α-substituted heterocycles for asymmetric catalysis, their reactivity patterns against enolization, and resulting
Enabling technologies and green processes in cyclodextrin chemistry
Beilstein J. Org. Chem. 2016, 12, 278–294, doi:10.3762/bjoc.12.30
- preparation of CD thiols and thioethers is an emerging challenge because of the importance of intermediary azido derivatives [96] and favorable aggregation properties in nanomedicines and particularly the antidote Sugammadex [97]. The reaction between 6I-O-monotosyl-β-CD and various nucleophiles opens a new
Lewis acid-promoted hydrofluorination of alkynyl sulfides to generate α-fluorovinyl thioethers
Beilstein J. Org. Chem. 2015, 11, 1902–1909, doi:10.3762/bjoc.11.205
- Davide Bello David O'Hagan University of St Andrews, School of Chemistry, North Haugh, St Andrews, Fife, KY16 9ST, UK 10.3762/bjoc.11.205 Abstract A new method for the preparation of α-fluorovinyl thioethers is reported which involves the hydrofluorination of alkynyl sulfides with 3HF·Et3N, a
- process that requires Lewis acid activation using BF3·Et2O and TiF4. The method gives access to a range of α-fluorovinyl thioethers, some in high stereoselectivity with the Z-isomer predominating over the E-isomer. The α-fluorovinyl thioether motif has prospects as a steric and electronic mimetic of
- thioester enols and enolates, important intermediates in enzymatic C–C bond forming reactions. The method opens access to appropriate analogues for investigations in this direction. Keywords: alkynyl sulfides; α-fluorovinyl thioethers; hydrofluorination; Lewis acids; organofluorine; Introduction
Advances in the synthesis of functionalised pyrrolotetrathiafulvalenes
Beilstein J. Org. Chem. 2015, 11, 1112–1122, doi:10.3762/bjoc.11.125
- functionalised with thioethers, exemplified by a series of ethylene glycol derivatives. Additionally, the merits of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) as an alternative to the most common deprotecting agent, CsOH·H2O are discussed. Finally, we show how a copper-mediated Ullman-type reaction can be applied
- -cyanoethyl-protected thiols as a means to further functionalise MPTTFs with thioethers and (ii) copper-mediated N-arylation of both MPTTFs and BPTTFs. Results and Discussion An improved large-scale synthesis of N-tosyl-(1,3)-dithiolo[4,5-c]pyrrole-2-one (6) The known compound 6 [4][25] is an important
- bearing a 2-cyanoethyl-protected thiol The 2-cyanoethyl protecting group offers a convenient means of synthesising MPTTFs where one or both of R1 and R2 are thioethers. When only simple alkyl thioethers are targeted, it is often more effective to incorporate these moieties prior to the cross-coupling step
Electrochemical oxidation of cholesterol
Beilstein J. Org. Chem. 2015, 11, 392–402, doi:10.3762/bjoc.11.45
- reaction carried out with 1,2:3,4-di-O-diisopropylidene-α-D-galactopyranose yielded glycoconjugate 23 with an ether bond between the sugar and steroid molecules. In further studies on the preparation of glycoconjugates from 3β-hydroxy-Δ5-steroids, various derivatives were applied, such as thioethers [44
3α,5α-Cyclocholestan-6β-yl ethers as donors of the cholesterol moiety for the electrochemical synthesis of cholesterol glycoconjugates
Beilstein J. Org. Chem. 2015, 11, 162–168, doi:10.3762/bjoc.11.16
- derivatives show similar reactivities to those of previously studied 3α,5α-cyclocholestan-6β-thioethers. Keywords: cholesterol; electrochemical oxidation; glycosylation; i-cholesteryl ethers; i-steroids; Introduction We have recently elaborated an electrochemical method for the preparation of glycosides and
- cholesterol wins the competition, the dimer 2 (dicholesteryl ether) is formed. A large excess of sugar was used to avoid this undesired side reaction. In our further study, instead of cholesterol, cholest-5-en-3β-yl and 3α,5α-cyclocholestan-6β-yl thioethers (3 and 4) were applied as cholesteryl donors [4]. Of
- the two, the latter appeared to be much more efficient in cholesteryl transfer to the sugar moiety. The problem, however, with 6β-steroidal thioethers is that they are not easily accessible. Therefore, we searched for the best leaving group at C-3. A series of cholesterol derivatives was tested and
Synthesis of uniform cyclodextrin thioethers to transport hydrophobic drugs
Beilstein J. Org. Chem. 2014, 10, 2920–2927, doi:10.3762/bjoc.10.310
- affinity towards rocuronium [24][25]. Furthermore, hydrophilic γ-CD thioethers show high affinities to other guests such as polycyclic aromatic hydrocarbons [26], botulin [27][28], and fullerene C60 [29]. Hydrophilic β-CD thioethers also tightly complex volatile benzene derivatives leading to a significant
- decrease of their vapour pressure [30]. Therefore we were encouraged to investigate the inclusion of volatile hydrophobic APIs, e.g., sevoflurane, in CD thioethers. Sevoflurane, a versatile inhalational anaesthetic [31], was already included in native CDs and hydroxypropyl-β-CD, but these complexes are
- either nearly insoluble in water or the binding constants are rather low [32][33][34]. We focussed our effort on the design of hydrophilic and/or amphiphilic CD thioethers, because only amphiphilic molecules can form [35][36] or incorporate into bilayer membranes [37][38]. Amphiphilic CD carriers can
Synthesis of nanodiamond derivatives carrying amino functions and quantification by a modified Kaiser test
Beilstein J. Org. Chem. 2014, 10, 2729–2737, doi:10.3762/bjoc.10.288
- nitrogen and sulfur content. All analytical methods yield comparable results around 0.2 mmol g−1. The further reaction depicted in Scheme 1 enables the formation of an aromatic amine at the 2-position of the ring by the oxidation of the thioethers and subsequent substitution of the sulfone by an amino
- function. Throughout the transformation the surface loading (see TGA data and elemental analysis in the experimental part) with the organic moieties remains the same showing the high stability of the double grafting by covalent C–C bonds. However, during the oxidation of the thioethers to the sulfones a
Chiral phosphines in nucleophilic organocatalysis
Beilstein J. Org. Chem. 2014, 10, 2089–2121, doi:10.3762/bjoc.10.218
Postsynthetic functionalization of glycodendrons at the focal point
Beilstein J. Org. Chem. 2014, 10, 1482–1487, doi:10.3762/bjoc.10.152
- expected in case of the glycodendrons 3–9. However, the so-called “thiol-ene” reaction [10] gave reliable results with both bivalent and tetravalent glycodendrons. The radical addition of mercaptododecane to either 3 or 7, employing AIBN as radical starter, led to the amphiphilic thioethers 12 and 13
- , respectively, in fair yields. Deprotection conditions employing TFA in water left the thioethers intact. These results were encouraging for further postsynthetic modification of glycodendrons. In a second part of our study we have investigated olefin cross metathesis [11] of polyether di- and tetravalent
Regioselective SN2' Mitsunobu reaction of Morita–Baylis–Hillman alcohols: A facile and stereoselective synthesis of α-alkylidene-β-hydrazino acid derivatives
Beilstein J. Org. Chem. 2014, 10, 990–995, doi:10.3762/bjoc.10.98
- [13][14], ethers [15][16], amines [17][18], thioethers [19], phosphonates [20][21], alkyl groups [22][23], and so on. In this context, however, reports on the conversion of MBH alcohols into hydrazine derivatives are scanty. In 2009, Nair and co-workers [24] reported an interesting reaction of MBH
End-group-functionalized poly(N,N-diethylacrylamide) via free-radical chain transfer polymerization: Influence of sulfur oxidation and cyclodextrin on self-organization and cloud points in water
Beilstein J. Org. Chem. 2014, 10, 680–691, doi:10.3762/bjoc.10.61
- [5] or of optical sensors [6]. Certain stimuli-responsive materials are characterized by the presence of thioethers in the main chain. Tirelli et al. investigated the oxidation-responsive behavior of thioethers for biomedical applications [7][8][9][10]. The stimulus of these mostly poly(propylene
- sulfide) containing copolymers is based on the oxidation of thioethers to more hydrophilic sulfoxides or sulfones [11][12]. The specific sulfoxidation of a polymer bound end-group, which is in the focus of our present work, has not yet been investigated. Polymeric materials exhibiting sensitivity to
Direct and indirect single electron transfer (SET)-photochemical approaches for the preparation of novel phthalimide and naphthalimide-based lariat-type crown ethers
Beilstein J. Org. Chem. 2014, 10, 514–527, doi:10.3762/bjoc.10.47
- understanding of the factors controling the chemical selectivities and efficiencies. For example, we have demonstrated that intramolecular SET-photochemical reactions of linked α-trimethylsilyl n-electron donor-phthalimides/naphthalimides produce functionalized macrocyclic poly-ethers, -thioethers, -amides, and
Silica: An efficient catalyst for one-pot regioselective synthesis of dithioethers
Beilstein J. Org. Chem. 2014, 10, 26–33, doi:10.3762/bjoc.10.5
- number of procedures have been developed to synthesize bis(thioethers) with varying degrees of success and a variety of limitations [19][20][21][22][23][24][25][26][27][28][29][30][31]. Over the last decade, organic synthesis has taken a major turn towards developing reaction conditions that are
- substitution–hydrothiolation processes (Scheme 1). Although both reactions are well-known, a search in the literature surprisingly revealed no general one-pot protocols for the preparation of dithioethers from allylic substrates. Recently, Banerjee and co-workers reported on the simple synthesis of thioethers
- showed varying results under conditions A or B, and allyl acetate did not undergo any desired reaction, but merely produced the disulfide from oxidative dimerization of the thiol (Table 1, entries 6–8). Allyl tosylate, however, produced the desired thioethers in a regioselective manner, but with
Synthesis and antibacterial activity of monocyclic 3-carboxamide tetramic acids
Beilstein J. Org. Chem. 2013, 9, 1899–1906, doi:10.3762/bjoc.9.224
- generality [20][21]. We found that an approach based upon direct acylation of methyl thioethers 8a,b (these were readily obtained from the required N-acylmethionine by DCC/DMAP coupling with Meldrum’s acid and cyclisation under reflux) was possible, which made use of the high acidity of the tetramate system
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