Halides, acyl from alcohols

Oxygen abstraction reactions from alcohols, ketones, acyl halides and other oxygen-containing compounds by MCI or related derivatives also afforded a route to relatively simple complexes of the oxo halides (Table 24). Thus Nb2Cli0 was found to abstract oxygen from higher ketones to yield, after hydrolysis, alkanes, chloroalkanes or arylalkanes.414... 

Schotten-Baumann reaction The formation of an ester or amide from an acyl halide with an alcohol or an amine respectively when reacted with aqueous alkali. 

Carboxylic, and arylsulfonic acid halides react rapidly with pyridines generating 1-acyl- and 1-arylsulfonyl-pyridinium salts in solution, and in suitable cases some of these can even be isolated as crystalline, non-hygroscopic sohds. Solutions of these salts, generally in excess pyridine, are commonly used for the preparation of esters and sulfonates from alcohols, and of amides and sulfonamides from amines. 

Monothioacetals 1,3-Oxathiolanes Thiolactams S extrusion, 59-60, 261 Thiols synthesis from haloalkanes, 169, 269 Thionation of lactones, 110-111 Thiones olefination of, 35 Thionocarbonates. See Carbonothioates Thionolactones, 110-111 Thionyl chloride prepn. of acyl halides, 143 prepn. of carboxylic esters, 347 prepn. of haloalkanes from alcohols, 32 Thiophenoi. See Benzenethiol Thiotosylatc. See Benzenesulfonothioic add... 

Pd nanoparticles supported on PANI-NFs are efficient semi-heterogeneous catalysts for Suzuki coupling between aryl chlorides and phenylboronic acid, the homocoupling of deactivated aryl chlorides, and for phenol formation from aryl halides and potassium hydroxide in water and air [493], PANl-NF-supported FeCl3 as an efficient and reusable heterogeneous catalyst for the acylation of alcohols and amines with acetic acid has been presented [494]. Vanadate-doped PANI-NFs and PANI-NTs have proven to be excellent catalysts for selective oxidation of arylalkylsulfides to sulfoxides under nuld conditions [412]. Heterogeneous Mo catalysts for the efficient epoxidation of olefins with ferf-butylhydroperoxide were successfully synthesized using sea urchin-Uke PANI hollow microspheres, constructed with oriented PANI-NF arrays, as support [495]. Pt- and Ru-based electrocatalyst PANI-NFs—PSSA—Ru—Pt, synthesized by the electrodeposition of Pt and Ru particles into the nanofibrous network of PANI-PSSA, exhibited an excellent electrocatalytic performance for methanol oxidation [496]. A Pt electrode modified by PANI-NFs made the electrocatalytic oxidation reaction of methanol more complete [497]. Synthesis of a nanoelectrocatalyst based on PANI-NF-supported... 

This reaction has wide application in the preparation of esters from alcohols and acylation reagents (e.g., acyl halides and anhydrides). 

This reaction was first reported by Schotten in 1884 and subsequently extended by Baumann in 1886. It is the acylation of alcohols and amines from acyl halide or anhydride in an aqueous alkaline solution (e.g., 1 M NaOH), and is generally known as the Schotten-Baumann reaction or Schotten-Baumann acylation. Occasionally, it is also referred to as the Schotten-Baumann method,or Schotten-Baumann esterification. Likewise, the formation of benzoyl ester under these conditions is called the Schotten-Baumann benzoylation." It is assumed that the reaction would perform well if carried out in a biphasic system of water and an immiscible organic solvent (e.g., CH2CI2), which has an important application in the acylation of amino acids.For example, p-nitrohippuric acid and dibenzoylornithine (ornithuric acid) all can be prepared under these conditions. 

Friedel-Crafts acylation 44, 956 halides from alcohols via xanthates 44,430... 

The conversion of carboxylic acids into acyl halides employs the same reagents used in the synthesis of haloalkanes from alcohols (Section 9-4) SOCI2 and PBrs. The problem to be solved in both cases is identical—changing a poor leaving group (OH) into a good one. 

The chemical transformations of the carboxyl group include formation of halo[ C]acetyl halides, amides, imides, alcohols, aldehydes and amines. Methods for the preparation of halo[ " C]acetyl halides from [ " C]acetic acid have already been mentioned. In addition, chloro[ " C]acetyl chloride has become available through treatment of chloro[ C]acetic acid with thionyl chloride or phthaloyl chloride, whereas for bromo[ " C]acetyl chloride, thionyl chloride or phosphorus pentachloride is recommended. Numerous applications of halol Clacetyl halides have been published, out of which the following C-, N- and 0-acylations may illustrate their versatility. 

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