Amines phenyl selenides

Phenyl selenides.2 In the presence of a ruthenium catalyst, prepared by reaction of RuCly with 3 equivalents of potassium, lithium benzencselenolate reacts with a wide variety of tertiary amines to form phenyl selenides in excellent yield. Anhydrous diglyme is used as solvent. 

Alkyl phenyl setenides selenol esters. N-PhcnylscIcnophthalimidc is superior to aryl selenocyanates for conversion of alcohols to alkyl phenyl selenides (6, 252-253) and of carboxylic acids to selenol esters (7, 396-397). When conducted in the presence of an amine the latter reaction provides amides in high yield (equation l). ... 

Ally lie amines (12,121). Coupling of allylic phenyl selenides with aliphatic or aromatic primary amines is possible if the selenide is treated with NCS and N(C2H5)3 in CH3OH at -25° prior to the addition of the amine. Yields are only modest in coupling of highly substituted selenides or amines.1 Example ... 

Optically active amino acids The NCS-promoted rearrangement of allylic phenyl selenides (12,121) when applied to an optically active substrate (1), available from ethyl (S)-lactate, results in an allylic amine (2), which can be converted into an optically active N-protected D-amino acid (3) in 78-84% ee. 

Allylic amines. Ally lie phenyl selenides on reaction with NCS (excess), an alkyl carbamate, and triethylamine at room temperature are converted into the corresponding rearranged carbamate-protected primary allylic amines. 

Dealkylation of amines. Most amines (primary, secondary, and tertiary) form crystalline salts with benzeneselenol. When heated (150°) some of these salts decompose to form the dealkylated amine and an alkyl phenyl selenide. Salts of primary alkylamines for unknown reasons undergo dealkylation very slowly hindered, tertiary amines are dealkylated most rapidly. 

As with amine oxides and sulfoxides, acyclic 1,2-disubstituted alkenes are usually obtained with the ( )-stereochemistry, although the formation of a,(3-unsaturated nitriles is reported to give a mixture of ( )- and (Z)-isomers. For cyclic alkenes, the stereochemistry of double bond formation depends upon ring size. However, it can be affected by conformational factors, e.g. cyclododecyl phenyl selenide gives a mixture of cis- and fra/is-cyclododecenes on oxidative elimination (equation 38) but only the (El-isomer (101) was obtained from the acetoxycyclododecyl selenide (100 equation 39). ... 

ArsBi bearing ortho methoxy groups mediates dehydrative condensation of a-monosubstituted carboxylic acids with alcohols and amines (Scheme 14.139) [288]. Macrocyclic esters can be synthesized by the ArsBi-templated reaction of diols with dicarboxylic acid derivatives [289]. The Bi-C bonds of Ar Bi are cleaved by diphenyl diselenide and ditelluride to give aryl phenyl selenides and tellurides, respectively (Scheme 14.140) [290]. The reaction of ArsBi with elemental chalcogen (E Se, Te) affords a mixture of the respective dichalcogenides (ArEEAr) and monochalcogenides (ArEAr). 

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