Sulfonic acid amides disulfides

Thiocyanates can often be utilized as intermediates in the Reparation of other sulfur-containing compounds, alkylthiocarbonic acid amides, disulfides, mercaptans, sulfides, and sulfonic acids. Typical reactions are as follows ... 

In general, aldehydes, ketones, acids, esters, and acid chlorides are all reduced to the corresponding alcohols hy this reagent. Alkyl halides are unreactive towards DIBAL. Amides are reduced to amines, while nitriles afford aldehydes upon hydrolysis of an intermediate imine. Isocyanates are also reduced to the corresponding imines. Nitro compounds are reduced to hydroxy-lamines. Disulfides are reduced to thiols, while sulfides, suhbnes, and sulfonic acids are unreactive in toluene at 0°C. Tosylates are converted quantitatively to the corresponding alkanes. Cyclic imides can be reduced to carbinol lactams. 

The earlier studies and the competition experiments [5b] with equivalent molar, enal, or enone 9-BBN (3-5% excess) reveal that enals or enones are selectively reduced to allylic alcohols (Eq. 25.9) in the presence of other organic functional groups such as nitro, halogen, epoxide, carboxylic acid, amide, ester, nitrile, sulfide, disulfide, sulfoxide, sulfone, tosylate, azo, etc. 

In summary, the reactivity of various functional groups toward Li 9-BBNH is classified into four broad categories [18] (1) rapid- or fast-reduction aldehyde, ketone, ester, lactone, acylchloride, acid anhydride, epoxide, disulfide, -alkyli-odide, and tosylate (2) slow-reduction tertiary amide, alkylbromide, and aromatic nitrile (3) sluggish-reduction carboxylic acid, aliphatic nitrile, primary amide, nitro and azoxy compounds, and secondary alkylbromide and tosylate (4) inert olefin, oxime, alkylchloride, sulfoxide, azo-compound, sulfide, sulfone, and sulfonic acid. 

Thermal Stability. Dimethyl sulfoxide decomposes slowly at 189°C to a mixture of products that includes methanethiol, formaldehyde, water, bis(methylthio)methane, dimethyl disulfide, dimethyl sulfone, and dimethyl sulfide. The decomposition is accelerated by acids, glycols, or amides (30). This product mixture suggests a sequence in which DMSO initially undergoes a Pummerer reaction to give (methylthio)methano1, which is labile and reacts according to equations 1—3. Disproportionation (eq. 4) also occurs to a small extent ... 

The at complex from DIB AH and butyllithium is a selective reducing agent.16 It is used tor the 1,2-reduction of acyclic and cyclic enones. Esters and lactones are reduced at room temperature to alcohols, and at -78 C to alcohols and aldehydes. Acid chlorides are rapidly reduced with excess reagent at -78 C to alcohols, but a mixture of alcohols, aldehydes, and acid chlorides results from use of an equimolar amount of reagent at -78 C. Acid anhydrides are reduced at -78 C to alcohols and carboxylic acids. Carboxylic acids and both primary and secondary amides are inert at room temperature, whereas tertiary amides (as in the present case) are reduced between 0 C and room temperature to aldehydes. The at complex rapidly reduces primary alkyl, benzylic, and allylic bromides, while tertiary alkyl and aryl halides are inert. Epoxides are reduced exclusively to the more highly substituted alcohols. Disulfides lead to thiols, but both sulfoxides and sulfones are inert. Moreover, this at complex from DIBAH and butyllithium is able to reduce ketones selectively in the presence of esters. 

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