Atropisomeric [(diphosphine)Au2Cl2] complexes and their catalytic activity towards asymmetric cycloisomerisation of 1,6-enynes
File(s)
Published version
Author(s)
Barreiro, EM
Boltukhina, EV
White, AJP
Hii, K
Type
Journal Article
Abstract
KGaA. X-ray crystal structures of two [(diphosphine)-Au2Cl2] complexes (in which diphosphine = P-Phos and xylyl-P-Phos; P-Phos = [2,2′,6,6′-Tetramethoxy-4,4′-bis(diphenylphosphino)-3,3′-bipyridine]) were determined and compared to the reported structures of similar atropisomeric gold complexes. Correlations between the Au⋯Au distances and torsional angles for the biaryl series of ligands (MeOBIPHEP, SEGPhos, and P-Phos; BIPHEP = 2,2′-bis(diphenylphosphino)-1,1′-biphenyl, SEGPhos = [(4,4′-bi-1,3-benzodioxole)-5,5′-diyl]-bis[diphenylphosphine]) can be made; these measurements appear to be very dependent upon the phosphorous substituent. Conversely, the same effect was not observed for ligands based on the binaphthyl (BINAP) series. The catalytic activity of these complexes was subsequently assessed in the enantioselective cycloisomerisation of 1,6-enynes and revealed an over-riding electronic effect: more-electron-rich phosphines promote greater enantioselectivity. The possibility of silver acting as a (co-)catalyst was ruled out in these reactions.
Date Issued
2014-12-11
Date Acceptance
2014-07-21
Citation
Chemistry - A European Journal, 2014, 21 (6), pp.2686-2690
ISSN
0947-6539
Publisher
Wiley
Start Page
2686
End Page
2690
Journal / Book Title
Chemistry - A European Journal
Volume
21
Issue
6
Copyright Statement
© 2015 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA. This is an open access article under the terms of Creative Commons Attribution NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made
License URL
Identifier
http://www.ncbi.nlm.nih.gov/pubmed/25504519
Publication Status
Published