Premium
Controlled, Sequential approach to Synthesize Stereogenic Methanes via in situ Generated Reactive Intermediates
Author(s) -
Harikrishnan Adhikesavan,
Gnanasekaran Ramachandran,
Ramanathan Chinnasamy Ramaraj
Publication year - 2016
Publication title -
chemistryselect
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 34
ISSN - 2365-6549
DOI - 10.1002/slct.201600650
Subject(s) - carbocation , nucleophile , chemistry , stereocenter , catalysis , alkylation , aldehyde , bond cleavage , in situ , reactive intermediate , combinatorial chemistry , cleavage (geology) , medicinal chemistry , stereochemistry , organic chemistry , computational chemistry , enantioselective synthesis , fracture (geology) , geotechnical engineering , engineering
A facile and straightforward synthesis of unsymmetrical triarylmethanes and stereogenic methanes have been realized through the Friedel‐Crafts type alkylation of arenes with alkoxyaluminium intermediate generated in situ from aldehyde, arene and AlBr 3 at room temperature in presence of catalytic quantity of AlBr 3 . This protocol is successful with diversity of starting materials and desired products were obtained in moderate to good yields. The displacement of ‐OAlBr 2 with catalytic quantity of AlBr 3 generated the reactive carbocation like intermediate which underwent subsequent reaction with another nucleophile (either ‐C, ‐S or –O nucleophile) and furnished the corresponding substituted products. The mechanism of the controlled, sequential reaction has been investigated by density functional theory calculations. Our model suggests that the involvement of penta coordinate complex in which the cleavage of C−OAlBr 2 bond is favoured over N−AlBr 2 bond at room temperature, in presence of additional catalyst.