90927-72-3Relevant academic research and scientific papers
Metallation reactions. XXI. Metallation of alkyl (alkylthio) benzenes by superbases versus organolithium compounds
Cabiddu, Salvatore,Fattuoni, Claudia,Floris, Costantino,Melis, Stefana,Serci, Alessandro
, p. 6037 - 6048 (2007/10/02)
The metallation regiochemistry of alkyl(alkylthio)benzenes with butyllithium or with the superbasic mixture of butyllithium with potassium tert-butoxide is described. The reaction pattern depends on the substrate and the reagent. Butyllithium monometallates the thiomethylic carbon of methyl (methylthio) benzenes and bimetallates the thiomethylic and the annular carbon ortho to the thioethereal group. With superbases the metallation occurs at the thiomethylic and methylic carbon. Metallation with butyllithium of the higher homologs substitutes exclusively the hydrogen ortho to the thioalkylic group, while the superbases attack also the carbon atom alpha to the thioalkyl substituent.
METALATION REACTIONS. XIV. REGIOSPECIFIC PREPARATION OF POLYSUBSTITUTED BENZENES VIA MONO- OR DI-LITHIATION REACTIONS OF AROMATIC THIOETHERS
Cabiddu, Salvatore,Fattuoni, Claudia,Floris, Costantino,Gelli, Gioanna,Melis, Stefana,Sotgiu, Francesca
, p. 861 - 884 (2007/10/02)
The preparation of polyfunctionalized aromatic thioethers either by one-step dilithiation or by two successive one-flask monometalation reactions is described.By acting on 1 two equal or different electrophiles one on the thiomethyl group and one in the ortho-position with respect to it are introduced; by acting on 11 and on 35 the substitution involves the thiomethyl carbon atom and that in the ortho-position with respect to the alkoxy group.In the case of the homologeous isopropylthio (23) the substitution involves the two aryl carbon atoms in the ortho-position to both functions.In the case of the p-disubstituted isomers (49, 59) analogous behaviour to ortho isomers in one-step metalation reaction is observed, while the two hydrogen atoms in the ortho-positions to the methoxy group are substituted when two successive monometalations are employed.The metalation of 40 results low selective.The behaviour of 79 and 93 is analogous to 1, while 72, 88 and 96 undergo only one-step monometalation reactions.
Metalation reactions XIII. The reactions of electrophiles with the dilithiated species 1-(α-lithiomethyl)-2-benzene
Cabiddu, S.,Floris, C.,Gelli, G.,Melis, S.
, p. 1 - 10 (2007/10/02)
Direct dimetalation of 1-methyl-2-(methylthio)benzene (1) gives the dilithiated species (2) in good yield, which can be used to introduce substituents into the thiomethyl and methyl groups.Species 2 can react also with a variety of dichlorosilanes and dichlorostannanes, and with sulphur chloride, to yield derivatives of 1,3-benzothiasilin, 1,3-benzothiastannin and 1,3-benzodithiin respectively.Reaction of 2 with tetrachlorosilane yields a spirocyclic silicon compound, while reaction with benzoyl chloride yields a derivative of 1-benzothiopyran.
