874907-58-1Relevant articles and documents
The abnormal behavior of an atropisomer: 3,3′-dibromo-1,1′- difluoro-2,2′-binaphthyl reacting with alkyllithium compounds
Leroux, Frederic,Mangano, Giuseppe,Schlosser, Manfred
, p. 5049 - 5054 (2007/10/03)
1-Fluoro-2-(triethylsilyl)naphthalene (1) and other 1-fluoronaphthalenes bearing a metalation-resistant substituent at the 2-position proved to be totally inert toward base attack. 3-Bromo-1-fluoronaphthalene (6), readily prepared from the 2-bromo isomer 5 by deprotonation-triggered heavy halogen migration, was converted into 3,3′-dibromo-1,1′-difluoro-2,2′- binaphthyl (8) by consecutive treatment with lithium diisopropylamide, copper(II) bromide and nitrobenzene. The dilithiated intermediate generated from the atropisomer 8 by treatment with 2 equiv. of butyllithium reacted with a variety of electrophiles to afford products such as the diacid 12 or the bis(phosphanes) 14 and 15 in high yields. The latter compound was also obtained in a straightforward manner from (4-fluoro-2-naphthyl)diphenylphosphane oxide (16). Unexpectedly, neither the 3,3′-dibromobinaphthyl 8 nor its 3,3′-diiodo analogue 18 were amenable to a unilateral but only to a double-sided halogen/metal permutation. Wiley-VCH Verlag GmbH & Co. KGaA, 2005.
