Record Details

Intramolecular interactions between chalcogen atoms: organoseleniums derived from 1-bromo-4-tert-butyl-2,6-di(formyl)benzene

DSpace at IIT Bombay

View Archive Info
 
 
Field Value
 
Title Intramolecular interactions between chalcogen atoms: organoseleniums derived from 1-bromo-4-tert-butyl-2,6-di(formyl)benzene
 
Creator ZADE, SS
PANDA, S
SINGH, HB
SUNOJ, RB
BUTCHER, RJ
 
Subject und ihrer derivate
glutathione-peroxidase activity
chiral selenium electrophiles
se-77 nmr-spectroscopy
x-ray crystallography
stable selenenic acid
se-c atoms
crystal-structure
molecular-structure
asymmetric methoxyselenenylation
 
Description The synthesis and characterization of a series of low-valent organoselenium compounds derived from 1-bromo-4-tert-butyl-2,6-di(formyl)benzene (22) is described. The synthesis of diselenide 25 was achieved by the lithiation route whereas bis(4-tert-butyl-2,6-di(formyl)phenyl) diselenide (26) was synthesized by treating 22 with disodium diselenide. A series of monoselenides (27, 28, and 29) was obtained by facile nucleophilic substitution of bromine in 22, using the corresponding selenolates as nucleophiles. The halogenation reactions of bis(4-tert-butyl-2,6-di(formyl)phenyl) diselenide (26) did not afford the corresponding selenenyl halides but resulted in the isolation of an unexpected cyclic selenenate ester 34 as a product. The selenide 32 was synthesized by the treatment of dimethoxymethyl diselenide with trilithiated 2-bromo-5-tert-butyl-NM-di(phenyl)isophthalamide. The existence of potential (SeO)-O-... intramolecular nonbonding interactions was examined by IR, H-1, and Se-77 NMR spectroscopy, X-ray crystallography, and computational studies. The X-ray crystal structures of 26 and 27, having two ortho formyl groups, reveal the absence of any (SeO)-O-... interactions. However, the (SeO)-O-... interactions were observed in the selenenate ester 34 where one of the formyl groups has been utilized for the selenenate ring formation. The crystal structures of 26 and 27 exhibited intermolecular short-range C-H... Se interactions (hydrogen bonding). Although there are four heteroatoms in carbamoyl moieties ortho to selenium capable of forming a five-membered ring on intramolecular coordination, no such intramolecular (SeX)-X-... (X = N, O) interaction was observed in the crystal structure of 32. The density functional theory calculations at the B3LYP/6-31G* level predicted that for all the diformyl systems (47a-c, 48a-c), the anti,anti conformer (when both formyl oxygen atoms point away from the selenium) is more stable. This preference was found to be reversed in the monoformyl-substituted systems (50a,b, 51a,b), where the syn conformer (when formyl oxygen is near the selenium) is energetically more favorable than the anti conformer.
 
Publisher AMER CHEMICAL SOC
 
Date 2011-10-15T08:48:08Z
2011-12-15T09:16:24Z
2011-10-15T08:48:08Z
2011-12-15T09:16:24Z
2005
 
Type Review
 
Identifier JOURNAL OF ORGANIC CHEMISTRY,70(9)3693-3704
0022-3263
http://dx.doi.org/10.1021/jo0478656
http://dspace.library.iitb.ac.in/xmlui/handle/10054/13961
http://hdl.handle.net/100/3153
 
Language en