1398654-89-1Relevant academic research and scientific papers
Atropisomeric [(diphosphine)Au2Cl2] complexes and their catalytic activity towards asymmetric cycloisomerisation of 1,6-enynes
Barreiro, Elena M.,Boltukhina, Ekaterina V.,White, Andrew J. P.,Hii, King Kuok Mimi
, p. 2686 - 2690 (2015)
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.
One-point binding ligands for asymmetric gold catalysis: Phosphoramidites with a TADDOL-related but acyclic backbone
Teller, Henrik,Corbet, Matthieu,Mantilli, Luca,Gopakumar, Gopinadhanpillai,Goddard, Richard,Thiel, Walter,Fuerstner, Alois
supporting information, p. 15331 - 15342 (2012/11/07)
Readily available phosphoramidites incorporating TADDOL-related diols with an acyclic backbone turned out to be excellent ligands for asymmetric gold catalysis, allowing a number of mechanistically different transformations to be performed with good to outstanding enantioselectivities. This includes [2 + 2] and [4 + 2] cycloadditions of ene-allenes, cycloisomerizations of enynes, hydroarylation reactions with formation of indolines, as well as intramolecular hydroaminations and hydroalkoxylations of allenes. Their preparative relevance is underscored by an application to an efficient synthesis of the antidepressive drug candidate (-)-GSK 1360707. The distinctive design element of the new ligands is their acyclic dimethyl ether backbone in lieu of the (isopropylidene) acetal moiety characteristic for traditional TADDOLs. Crystallographic data in combination with computational studies allow the efficiency of the gold complexes endowed with such one-point binding ligands to be rationalized.
