Substitution reaction of alcohols

K. Motokura, N. Nakagiri, T. Mizugaki, K. Ebitani, and K. Kaneda, Nucleophilic substitution reactions of alcohols with use of montmorillonite catalysts as solid Br0nsted acids, J. Org. Chem., 72 (2007) 6006-6015. 

Nucleophilic substitution reaction of alcohol with ammonia MOR, RHO, CHA, FAU... 

Many industrially important substitution reactions of alcohols arc conducted in the vapor phase over a catalyst. Only primary alcohols give satisfactory yields of product under these conditions. 

Mechanistic Studies.- A number of substitution reactions of alcohols, phenols, or amines with 1,3,2-dioxaphospholans, e.g. (73), oxazaphospholans, and diazaphos-pholans have been followed by n.m.r. and shown to involve H-phosphoranes, e.g. (74). The reactions are run in toluene or without solvent, and without addition of an acidic catalyst in some systems, with 4-chlorophenol as the nucleophile, an equilibrium was established between an H-phosphorane (75) and a phosphonium salt (76), but the authors still favour (75) as the true intermediate. The equilibrium constants for a series of exchange reactions between (thio)phosphites (77) and (thio)phosphoro-dichloridites (78), and some analogous bromidites and a fluoridite, have been measured.The constants increase with increased electron donor ability of R. 

Nucleophilic Substitution of Alcohols. The use of alcohols as electrophiles instead of halides and acetate compounds is an ideal method to prevent waste salt formation (Fig. 5). However, cataljdic substitution of the hydroxyl group in alcohols is difficult due to their poor leaving ability, which requires equimolar or greater amounts of reagents. Recently, several homogeneous catalysts, such as NaAuCh, InCla, ZrCh, La, Yb, Sc, Hf triflate, BCCeFsls, BF3, and p-toluenesulfonic acid have been used for nucleophilic substitution reactions of alcohols with amides (33), 1,3-dicarbonyl compounds (34), and allylsilanes (35). However, these catalysts are often limited by low catalytic activity and selectivity, can be difficult to reuse, and require the use of halogenated solvents. 

II. Substitution Reactions of Alcohols, Enols, and Phenols at Oxygen... 

Scheme 2 General mechanism for direct nucleophilic substitution reactions of alcohols by amines/ amides...

Nucleophilic Substitution Reactions of Alcohols Forming Alkyl Halides 483... 

Substitution reactions of alcohols using SOCI2 proceed by an 8 2 mechanism. Therefore, there is inversion of configuration at a stereogenic center. 

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