Dimethyl sulfide, derivative

Yoon Y. J. and Brimblecombe P. (2002) Modelling the contribution of sea salt and dimethyl sulfide derived aerosol to marine CCN. Atmos. Chem. Phys. 2, 17-30. 

Dimethyl sulfide is a useful precursor to sulfur ylids, reacting with iodomethane to give trimethylsulfonium iodide (609). When this salt was treated with n-butyllithium, deprotonation of the hydrogen on the a-carbon led to dimethylsulfonium methylid (610). Dimethyl sulfoxide also reacts with alkyl halides to give a sulfoxonium salt. When DMSO reacted with iodomethane, trimethylsulfoxonium iodide (611) was formed. As with the dimethyl sulfide derivative, treatment with a strong base such as -butyllithium generated the corresponding ylid, dimethylsulfoxonium methylid (612). 

The donor substituent perturbation of lone pair centers is transparently demonstrated in sulfides (Fig. 7). The parent molecule H2S exhibits for its Jt-type sulfur lone pair perpendicular to the molecular plane an ionization needle at 10.5 eV [20]. Two (H3C)3SiCH2 substituents broaden the needle considerably, indicating charge delocalization and lower its first vertical ionization potential by 2.5 eV = 241 kJ mol to 8.0 eV. In the dimethyl sulfide derivative with three RsSi substituents at the same carbon center, the total shift reaches almost 3 eV (Fig. 7), an amazing demonstration of the extreme donor power of P-trimethylsilyl substituents. Tremendous substituent perturbations are also observed at other lone-pair heterocenters such as nitrogen in amines [1, 2b], with the ionization energies IE] lowered from 10.85 eV in NH3 to 7.66 eV in N(CH2SiR3)3, a difference of 3.19 eV ... 

The camphor-derived P-hydroxyl-sulfonium yhde proved to be unusually efficient for the cyclopropanation of electron-deficient alkenes. For example, the reaction of salt 21b with a,P-unsaturated nitrile affords the desired cyclopropane in 61% yield and 96% ee. In comparison, the corresponding tetrahydrothiophene and dimethyl sulfide-derived sulfonium salts (23 and 24), which lack the hydroxyl group, only gave a trace amount of the desired cyclopropane (Scheme 20.21). 

Among chiral dialkylboranes, diisopinocampheylborane (8) is the most important and best-studied asymmetric hydroborating agent. It is obtained in both enantiomeric forms from naturally occurring a-pinene. Several procedures for its synthesis have been developed (151—153). The most convenient one, providing product of essentially 100% ee, involves the hydroboration of a-pinene with borane—dimethyl sulfide in tetrahydrofuran (154). Other chiral dialkylboranes derived from terpenes, eg, 2- and 3-carene (155), limonene (156), and longifolene (157,158), can also be prepared by controlled hydroboration. A more tedious approach to chiral dialkylboranes is based on the resolution of racemates. /n j -2,5-Dimethylborolane, which shows excellent enantioselectivity in the hydroboration of all principal classes of prochiral alkenes except 1,1-disubstituted terminal double bonds, has been... 

Reduction of 3,5,5-tris-aryl-2(5// )-furanones 115 (R, R, R = aryl) with dimethyl sulfide-borane led to the formation of the 2,5-dihydrofurans 116 in high yields. However, in the case of 3,4-diaryl-2(5//)-furanones 115 (R, R = aryl R = H or r = H R, R = aryl), the reduction led to a complicated mixture of products of which only the diarylfurans 117 could be characterized (Scheme 36) (88S68). It was concluded that the smooth conversion of the tris-aryl-2(5//)-furanones to the corresponding furan derivatives with the dimethylsulfide-borane complex in high yields could be due to the presence of bulky aryl substituents which prevent addition reaction across the double bond (88S68). 

The oxazaborolidines are easily prepared by heating ephedrine with borane dimethyl sulfide or the appropriate boronate ester. The aluminum reagent C is obtained by mixing ephedrine and trimethylaluminum. Borolidinc A is superior to its methyl derivative B and to the aluminum analog C. The diastereomeric borolidine obtained from borane and (S,S)-pseu-doephedrine failed to show any cnantioselectivity25. A variety of aromatic aldehydes can be enantioselectively alkylated in the presence of A, however, with heptanal the enantioselectivity is poor25. 

Nucleophilic catalysis is also observed with iodide ions. Fluoride ion does not form nitrosyl fluoride under diazotization conditions, as is to be expected from Pearson s hard and soft acids and bases principle which was discussed briefly in Section 3.2. More recently, nucleophilic catalysis has also been shown to occur with thiocyanate ion (SCN ), thiosulfate ion (HS2Of), dimethyl sulfide, and thiourea (H2NCSNH2) or its alkyl derivatives (see below). 

Rhodococcus sp. Strain T09 A Rhodococcus strain T09 was isolated by enrichment on media-containing BT. The desulfurization mechanism of this organism was reported to be similar to Gordonia sp. 213E due to the observation of similar intermediates however, the substrate specificity was different. The strain T09 could use 2-methyl, 3-methyl and 5-methyl BT apart from BT as sole source of sulfur for growth, but not 7-methyl or ethyl derivatives. Additionally, it could also use methyl thiobenzothiazole, marcaptobenzothiazole, as well as benzene sulfide, benzene sulfonate, biphenyl sulfinate, dimethyl sulfate, dimethyl sulfone, dimethyl sulfide, methane sulfonic acid, thiophene, and taurine as sole sulfur sources. However, it could not grow on DBT or DBT sulfone. 

The readily available benzotriazolyl derivative of dimethyl sulfide, compound 821, can be alkylated on a-carbon in a stepwise manner to provide (a,a-disubstituted)alkyl thioethers 823 (Scheme 131). Hydrolysis of these thioethers under mild conditions (5% H2S04 at room temperature) furnishes ketones 824 in high yields. The anion derived from mono substituted (benzotriazol-l-yl)methyl thioether 822 adds to butyl acrylate to give intermediate 826 that can be hydrolyzed to y-ketoester 825. In another example of reactivity of a-(benzotriazol-l-yl)alkyl thioethers, treatment of thioether 822 with BunLi followed by phenyl isocyanate converts it into a-ketoanilide 828, via intermediate adduct 827 <1998JOC2110>. 

Dimethyl sulfide is derived primarily from the enzymatic hydrolysis of dimethylsulfoniopropionate(CH3)2S+CH2CH2COO DMSP),an osmoregulatory compound produced by a wide variety of marine phytoplankton [313,317]. Intracellular DMSP hydrolysis has been shown in phytoplankton [318], in macro algae [319], and also in bacteria following uptake of DMSP from seawater [320]. Reported seawater concentrations of dissolved dimethyl sulfide (< 0.1-90 nM) and DMSP (1 -1000 nM) vary with increasing depth, spatially from coastal areas to the open ocean, and also temporally from winter to summer [313-316]. 

RCH=CHZ —> RCHJCHODialkylchloroboranes, obtained as the major products of hydroboration of 1-alkenes with monochloroborane complexed with dimethyl sulfide, are oxidized by PCC to aldehydes (66-68% yield). Similar oxidation of dialkylchloroboranes derived from cyclic alkenes with PCC gives ketones in 70-85% yield. 

In contrast to the rich chemistry of alkoxy- and aryloxyallenes, synthetic applications of nitrogen-substituted allenes are much less developed. Lithiation at the C-l position followed by addition of electrophiles can also be applied to nitrogen-containing allenes [10]. Some representative examples with dimethyl sulfide and carbonyl compounds are depicted in Scheme 8.73 [147, 157]. a-Hydroxy-substituted (benzotriazo-le) allenes 272 are accessible in a one-pot procedure described by Katritzky and Verin, who generated allenyl anion 271 and trapped it with carbonyl compounds to furnish products 272 [147]. The subsequent cyclization of 272 leading to dihydro-furan derivative 273 was achieved under similar conditions to those already mentioned for oxygen-substituted allenes. 

Dimethylhydrazine, N,N Unsymmetrical Dimethylhydrazine under Hydrazine Derivatives Dimethyl Sulfide under Sulfides, Disulfides Dinitrotoluene under Simple Aromatic Nitro Compounds... 

Figure 2.5. Nucleophile selectivities determined from product analysis for the reactions of ring-suhstituted 1-phenylethyl derivatives (X-l-Y) with azide ion, acetate ion and methanol in 50 50 (v/v) water/trifluoroethanol. The selectivities are plotted against the appropriate Hammett substituent constant or a. Leaving group Y ( ) ring-suhstituted benzoates ( ) chloride (T) dimethyl sulfide (A) tosylate.

For 1,4 addition to enones, the cuprates of the bislactim ethers have been found to be very useful [88AG(E)1194]. These are made by reacting the lithio derivatives with CuBr SMe2 in the presence of dimethyl sulfide. 

Oxidation of ethyl 7-allyl-10-methoxy-4-oxo-6,7-dihydro-4//-pyrimido-[2,l-a]isoquinoline-3-carboxylate (99) by ozone in methylene chloride at -70°C, then treatment of the mixture with dimethyl sulfide at ambient temperature for 1 h gave either 7-(2-oxoethyl)- or 7-(2,2-dimethoxyethyl) derivatives (105 and 106), depending upon whether methanol was used during the workup (78USP4127720). 

The terpenes used were mainly /3-pinene fractions provided by DRT (Soci6td des Derives Rdsiniques et Terpeniques, Vielle-S Girons) and, for certain experiments a turpentine oil containing the main three terpenes a-pinene, /3-pinene, and A -carene. The /3-pinene fractions contained 80-90% /3-pinene, 2% a-pinene, 4-5% myrcene, 2-3% dipentene and 700-1500 ppm S. GC-MS analyses showed that sulfur impurities were composed of alkyl and alkenyl sulfides (mainly dimethyl sulfide), alkyl and alkenyl disulfides (mainly dimethyl disulfide), trisulfides, thiophene and alkylthiophenes (methyl, dimethyl, acetyl and tertiobutyl). 

The photochemistry of 3-aryl-substituted l,4,2-dioxazol-2-in-5-ones (79) can be interpreted in terms of ring cleavage and loss of carbon dioxide with the formation of an acyl nitrene (80) such nitrenes are also formed by the photolysis of acid azides. In dimethyl sulfide, therefore, the 3-phenyl derivative itself (79 Ar=Ph) is converted into the photoproduct (81).05 When the phenyl group is substituted in... 

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