40400-26-8

Upstream product

• 36987-10-7 benzene-1,4-diselenol 
• 106-37-6 1.4-dibromobenzene 
• 77-78-1 dimethyl sulfate 
• 87136-97-8 p-(methylselenyl)phenyl isopropyl selenide 
• 74-88-4 methyl iodide 
• 35507-36-9 bis-(4-selenocyanato-phenyl)-diselenide 
• 7782-49-2 selenium 
• 87136-88-7 p-chlorophenyl isopropyl selenide 
• 106-46-7 para-dichlorobenzene 

Downstream Products

• 87137-10-8 p-(methylselenyl)phenyl ethyl selenide 

Relevant academic research and scientific papers

Frustrated rotations in single-molecule junctions

(Graph Presented) We compare the conductance of 1,4-bis(methylthio)benzene with that of 2,3,6,7-tetrahydrobenzo[1,2-b:4,5-b′]dithiophene and the conductance of 1,4-bis(methylseleno)benzene with that of 2,3,6,7- tetrahydrobenzo[1,2-b:4,5-b′]diselenophene a

A GENERAL PROCEDURE FOR THE SYNTHESIS OF METHYLTHIO-, METHYLSELENO- AND METHYLTELLURO-SUBSTITUTED AROMATIC COMPOUNDS

A one-pot procedure is described which allows the facile introduction of one or two methylchalcogeno groups into a variety of monobromo or dibromo aromatics.The bromo compounds were converted to their corresponding lithio derivatives by treatment with t-butyllithium in tetrahydrofuran at -78 deg C, and these derivatives were then treated, at ambient temperature with elemental sulfur, selenium, or tellurium.The resulting lithium thiolates, selenolates and tellurolates were finally methylated with methyl iodide to afford good yields (typically 50-80percent) of the various methylchalcogeno-substituted aromatic compounds.The procedure could not be used for the synthesis of ortho-disubstituted compounds, or for the simultaneous introduction of three methylchalcogeno groups.

Nucleophilic Aromatic Substitutions of Unactivated Aryl Halides by Methyl Selenide Anions. Synthesis and Selective Dealkylations of Aryl Alkyl Selenides

Lithium methyl selenide, easily prepared from powdered gray selenium and MeLi, reacts with unactivated aryl halides, in DMF, to afford the aryl methyl selenides as a result of a nucleophilic aromatic substitution.The aryl methyl selenides are rapidly dealkylated in the reaction medium by MeSeLi to give the aryl selenide anions.Addition of an alkyl halide or of cyanogen iodide gives rise to the formation of aryl alkyl selenides or aryl selenocyanates in good yields.From competitive experiments, carried out on compounds of the type ArClSeR and ArClSR, it has been shown that an RSe group is as efficient as an RS group in activating the nucleophilic aromatic substitution of a chlorine atom by MeS or MeSe anions in DMF. (Alkylthio)phenyl and alkoxyphenyl alkyl selenides can be selectively dealkylated by nucleophilic aliphatic substitution with MeSNa or MeSeLi in DMF or by electron transfer with sodium in HMPA.In the first case the easiness with which the dealkylation occurs follows the order ArSeMe > ArOMe > ArSMe, whereas in the second case the order is ArSeR > ArSR > ArOR.The synthetic utility of these reactions is exemplified and discussed.