Alcohols with thiols

VI.2.1.1.2 Pd-CATALYZED HYDROCARBOXYLATION 2347 TABLE 4. Pd-Catalyzed Thiocarbonylation of Allyl Alcohols with Thiols ... 

Xiao W, Alper H. The first examples of the palladium-catalyzed thiocarbonylation of propargyUc alcohols with thiols and carbon monoxide. J. Org. Chem. 1997 62 3422-3423. 

Inada Y, Nishiyashi Y, Kidai M, Uemura S. Ruthenium-catalyzed propagylic substitution reaction of propargylic alcohols with thiols a general route to propargylic sulfides. J. Am. Chem. Soc. 2002 124 15172-15173. 

Xiao WJ, Alper H (1998) Highly regioselective thiocarbonylation of allylic alcohols with thiols and carbon monoxide catalyzed by palladium complexes A new and efficient route to P,y-unsaturated thiol esters. J Org Chem 63 7939-7944... 

A major difference between alcohols and thiols concerns their oxidation We have seen earlier m this chapter that oxidation of alcohols gives compounds having carbonyl groups Analogous oxidation of thiols to compounds with C=S functions does not occur Only sulfur is oxidized not carbon and compounds containing sulfur m various oxida tion states are possible These include a series of acids classified as sulfemc sulfimc and sulfonic according to the number of oxygens attached to sulfur... 

Analogously, aldehydes react with ammonia [7664-41-7] or primary amines to form Schiff bases. Subsequent reduction produces a new amine. The addition of hydrogen cyanide [74-90-8] sodium bisulfite [7631-90-5] amines, alcohols, or thiols to the carbonyl group usually requires the presence of a catalyst to assist in reaching the desired equilibrium product. 

Vinyl chloride reacts with sulfides, thiols, alcohols, and oximes in basic media. Reaction with hydrated sodium sulfide [1313-82-2] in a mixture of dimethyl sulfoxide [67-68-5] (DMSO) and potassium hydroxide [1310-58-3], KOH, yields divinyl sulfide [627-51-0] and sulfur-containing heterocycles (27). Various vinyl sulfides can be obtained by reacting vinyl chloride with thiols in the presence of base (28). Vinyl ethers are produced in similar fashion, from the reaction of vinyl chloride with alcohols in the presence of a strong base (29,30). A variety of pyrroles and indoles have also been prepared by reacting vinyl chloride with different ketoximes or oximes in a mixture of DMSO and KOH (31). 

Aliphatic Alcohols and Thiols. Ahphatic alcohols on reaction with chloroformates give carbonates and hydrogen chloride. Frequendy, the reaction proceeds at room temperature without a catalyst or hydrogen chloride acceptor. However, faster reactions and better yields are obtained in the presence of alkaU metals or their hydroxides, or tertiary amines. Reactions of chloroformates with thiols yield monothiolocarbonates (14). 

TBDMSCl, imidazole, DMF, 25°, 10 h, high yields. This is the most common method for the introduction of the TBDMS group on alcohols with low steric demand. The method works best when the reactions are mn in very concentrated solutions. This combination of reagents also silylates phenols, hydroperoxides, and hydroxyl amines. Thiols, amines, and carboxylic acids are not effectively silylated under these conditions. ... 

Conflicting findings have been reported with thiols and in one case a hemiacetal was dehydrated to a dihydrofuran. A by-product found in varying amounts in the oxidation of secondary, cyclic alcohols is the corresponding thiomethoxymethyl ether. 

Mono-substitution occurs most readily in the stepwise replacement of the halogen substituents of 2,4,6-trichloro-s-triazine with aqueous methanol and sodium bicarbonate (30°, 30 min), the monomethoxy derivative (324) is obtained on heating (65°, 30 min), the disubstitu-ted derivative is formed and on brief heating (65°) with the more basic sodium carbonate or methanolic sodium hydroxide (25°, 3 hr) complete methoxylation (320) occurs. Ethanolic ethoxide (25°, 1 hr) or sodium carbonate (35°) is sufficient to give complete ethoxy-dechlorination. The corresponding phenoxy derivatives are obtained on treatment with one (0°), two (15°, 1 hr), or three equivalents (25-70°, 3 hr) of various sodium phenoxides in aqueous acetone. The stepwise reaction with phenols, alcohols, or thiols proceeds in better yield in organic solvents (acetone or chloroform) with collidine or 2,6-lutidine as acid acceptors than in aqueous sodium bicarbonate. ... 

A series of reactions was developed to transfer amines to ureido- and thioureido-derivatives for separation. The reaction of ureido-derivatives is widely used by the reaction with 1-phenylethyl isocyanate (PEIC) [8] or the naphthyl-analogue 1-(1-naphthyl)ethyl isocyanate (NEIC) [9]. Both reactions can be used not only for chiral amines but also for alcohols and thiols. 

Thiols, sometimes called mercaptcms, are sulfur analogs of alcohols. They are named by the same system used for alcohols, with the suffix -thiol used in place of -ol. The -SH group itself is referred to as a rnercapto group. 

Aldehydes and ketones react with thiols to yield thioacetals just as they react with alcohols to yield acetals. Predict the product of the following reaction, and propose a mechanism ... 

It may be noted that the additions of protonic molecules HA (alcohols, amines, thiols, etc. see Section III,C) to isocyanides may be related to these reactions, in the formalistic sense anyway, since they involve additions of A (in conjunction with H+) to the isocyanide. In a few instances the additions of HA can be accomplished by adding first A" and then H to the reactant species. However, no studies on HA additions have yet elucidated a mechanism for these reactions, so to draw a conclusion on the similarities of these reactions on mechanistic grounds is not appropriate. Because of this, and also for convenience, these subjects will be treated separately. 

A preparation of 3-substituted thiete dioxides takes advantage of the commercial availability of the parent four-membered thietanes. The latter is oxidized to the sulfone, which in turn is photochemically mono- or di-chlorinated in the 3-position. The 3-chlorothietane dioxide (239a) can be easily transformed into the thiete dioxide, whereas the 3,3-dichloro homolog is transformed into the 3-chloro-2H-thiete 1,1-dioxide (240b) (equation 91). 240b reacts with carbanions, amines, alcohols and thiols to give the corresponding 3-substituted thiete dioxides. ... 

Quaternary ammonium iodides were tested alone and in combination with propargyl alcohol with several steels in 15% HCl. The quaternary ammonium iodides showed superior inhibitor performance to that of propargyl alcohol (propargyl = —CH2-C=CH) at identical dosage levels. Mixtures of propargyl alcohol and quaternary anunonium iodide showed a synergistic effect [1330], as did formic acid [246] and thiols [1808]. 

In 2004, Yang and Tseng reported the synthesis of a series of new chiral amino thiol ligands derived from L-valine, which were further employed (1 mol%) in the enantioselective alkenylzinc addition to aldehydes, providing an efficient route for chiral ( )-allylic alcohols with enantioselectivities of up to >99% ee, as shown in Scheme 3.67. ... 

Quinone methides have been shown to be important intermediates in chemical synthesis,1 2 in lignin biosynthesis,3 and in the activity of antitumor and antibiotic agents.4 They react with many biologically relevant nucleophiles including alcohols,1 thiols,5-7 nucleic acids,8-10 proteins,6 11 and phosphodiesters.12 The reaction of nucleophiles with ortho- and /iara-quinone methides is pH dependent and can occur via either acid-catalyzed or uncatalyzed pathways.13-17 The electron transfer chemistry that is typical of the related quinones does not appear to play a role in the nucleophilic reactivity of QMs.18... 

The hydroxy groups in natural products like, for example, the macrolide antibiotics erythromycin, 1"1 and desmycosin, 2001 2011 as well as the 3-(hydroxymethyl)-2- or 3-cephems 2021 and derivatives of the amino sugar garamin 2031 have been converted into the carbamate function with CDI and amines. In the case of aminoglycoside antibiotics of the sisomicin series, thiocarbamates or dithiocarbamates have been prepared from alcohols or thiols using ImCSIm and amines.12041... 

Ethers and sulfides bearing the CF3CHFCF2- group are readily prepared by addition of the alcohol or thiol to hexafluoropropene. Some data from their fluorine spectra are given in Scheme 6.16, along with proton data. With the CHF carbon being chiral, the CF2 group should appear as an AB quartet. 

The base-catalyzed joint reaction of nitroalkenes with thiophenol in the presence of aldehydes gives y-phenylthio-P-nitro alcohols in one pot (Eq. 4.5).8 The joint reaction of nitroalkenes with thiols and a,p-unsaturated nitriles (or esters) has also been achieved. (Eq. 4.6).9 P-Nitro sulfides thus prepared show unique reactivity toward nucleophiles or tin radicals. The nitro... 

Ono and Kamimura have found a very simple method for the stereo-control of the Michael addition of thiols, selenols, or alcohols. The Michael addition of thiolate anions to nitroalkenes followed by protonation at -78 °C gives anti-(J-nitro sulfides (Eq. 4.8).11 This procedure can be extended to the preparation of a/jti-(3-nitro selenides (Eq. 4.9)12 and a/jti-(3-nitro ethers (Eq. 4.10).13 The addition products of benzyl alcohol are converted into P-amino alcohols with the retention of the configuration, which is a useful method for anri-P-amino alcohols. This is an alternative method of stereoselective nitro-aldol reactions (Section 3.3). The anti selectivity of these reactions is explained on the basis of stereoselective protonation to nitronate anion intermediates. The high stereoselectivity requires heteroatom substituents on the P-position of the nitro group. The computational calculation exhibits that the heteroatom covers one site of the plane of the nitronate anion.14... 

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