Thiophenol, reaction with

Me3SiCH2CH=CH2i TsOH, CH3CN, 70-80°, 1-2 h, 90-95% yield. This silylating reagent is stable to moisture. Allylsilanes can be used to protect alcohols, phenols, and carboxylic acids there is no reaction with thiophenol except when CF3S03H is used as a catalyst. The method is also applicable to the formation of r-butyldimethylsilyl derivatives the silyl ether of cyclohexanol was prepared in 95% yield from allyl-/-butyldi-methylsilane. Iodine, bromine, trimethylsilyl bromide, and trimethylsilyl iodide have also been used as catalysts. Nafion-H has been shown to be an effective catalyst. 

Enynes undergo a similar cyclization to alkylidene thioethers on reaction with thiophenol in the presence of AIBN. This cyclization also involves a vinyl radical (equation I).8... 

Imidoyl esters (Scheme 3.7) are obtained readily when the appropriate imidoyl chloride is reacted with an alcohol or phenol under basic conditions in the presence of phase-transfer catalysts [71]. The reaction with thiophenol yields the corresponding thioimidoyl ester. Diaroyl amides are produced by the analogous reaction of the imidoyl chloride and carboxylate anions. In this reaction, the initially formed carboxylic ester undergoes a 1,3-migration to produce the amide. 

It is not surprising that chloro esters 1, 2 readily add thiols, catalyzed by sodium thiolates or triethylamine, to give the corresponding 2-(r-organylthiocy-clopropyl)-2-chloroacetates 85,86 (Scheme 22) [15 b, 22b, 27]. This reaction with thiophenol has been used to quantify the Michael reactivity of 1-Me, 2-Me, 3-X in comparison to simple acrylates (see above). With an excess of PhSH, the nucleophilic substitution of the chlorine in 85 a (but not in 85h) proceeded to give the corresponding bis(phenylthio) derivative in 63% yield [15bj. Alkali thiolates (e.g. NaSMe, NaSBn) add smoothly onto 1-Me, 2c-Me and 2p-Me at - 78 °C, because at this temperature subsequent nucleophilic substitution of the chlorine is much slower [7l, 9]. The Michael additions of sodium phenylselenide and sodium arylsulfenates onto 1-Me and their synthetic utility have been discussed above (see Table 1). 

Dihydroazocines. Azocines can be converted into the corresponding iminium salts by treatment with 1 equiv of acid, such as methanesulfonic acid, in CHCI3. Nucleophilic additions to iminium salt 226 afforded substituted azocine derivatives reaction with thiophenol in DCM/H20 at room temperature provided 227, while reaction with sodium azide in CHCI3/DMF provided 228 (Scheme 92 <2005EJ01052>). 

The reaction of oxiranes with thiols permits the preparation of a-hydroxyalkyl thioethers. Reactions with thiophenols are presented in Eqs. 306 and 307.1 ... 

Methylsulfonyl groups activated by an adjacent nitro substituent are readily displaced in reaction with thiophenol and thiocresol anions <87AJC1415>. In a reaction believed to involve an intermediate... 

The reaction of [l,2,3]diazaphospholo[l,5-a]pyridine (22) with alcohol is completed only in the presence of sulfur or selenium and a catalytic amount of the respective sodium alkoxide to give 66. The reaction with thiophenol also occurs in the presence of sulfur to form 67 however no catalyst is required in this case (Scheme 24) [78],... 

In order to obtain isosteric sulfur and selenium analogs of retinyl ethers, the acetoxy group in retinyl acetate (9) was subjected to a nucleophilic substitution reaction with thiophenolate and selenophenolate to give (577) and (578), respectively (Welch and Gruber, 1979). The products were obtained in good yields, and the all-trans configuration was retained. 

Two alternative routes to (+)-swainsonine (ent-37S) developed by Chen and Tsai, Hke that used in their synthesis of lentiginosine (c Scheme 47 Section 3.3.2), created the bond to C-8a by means of free radical cycUzations onto an acylsilane. The first approach entailed the creation of the C-l/C-8a bond (Scheme 86). Amide formation between the amine 638 and the acid chloride prepared in situ from the chiral lactone-acid 639 yielded (—)-640, which was cyclized with base to the imide (—)-641 in 91% yield. Chemoselective reduction of the C-2 carbonyl group, acid-catalyzed reaction with thiophenol, and protection of the hydroxyl substituent as the benzoate gave 642 as a mixture of isomers. After hydrolysis of the dithiane to the acylsilane 643 with iodobenzene bis(trifluoroacetate), treatment with tri-butyltin hydride and l,lCazobis(cyclohexane-l-carbonitrile) (ACCN) as radical initiator produced the indohzidin-5-one 644 in 86% yield as a... 

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