149065-76-9Relevant articles and documents
Synthesis of modular thiophene-oxazoline ligands and their application in the asymmetric phenyl transfer reaction to aldehydes
Chai, Zhuo,Liu, Xin-Yuan,Wu, Xiao-Yu,Zhao, Gang
, p. 2442 - 2447 (2006)
A series of thiophene mono (oxazoline) N,O-ligands with three sites of diversity were synthesized concisely in two steps from the corresponding thiophene carbonitriles. These ligands were applied to the enantioselective phenyl transfer reaction of aldehydes, resulting in the corresponding chiral diaryl methanol products with excellent yields and moderate to good enantioselectivities.
A general and convenient route to oxazolyl ligands
Aspinall, Helen C.,Beckingham, Oliver,Farrar, Michael D.,Greeves, Nicholas,Thomas, Christopher D.
supporting information; experimental part, p. 5120 - 5123 (2011/10/19)
A diverse range of chiral and achiral oxazolyl ligands, which have many applications including catalysis and luminescent devices, are synthesized simply in three steps from readily available and inexpensive phenol and amino alcohol starting materials. The method can be applied to ligands with electron-donating/-withdrawing and sterically demanding/undemanding substituents, and can conveniently be scaled up to >25 g of product.
The application of Hetphox ligands to the asymmetric intermolecular heck reaction of 2,3-dihydrofuran and 2,2-disubstituted-2,3-dihydrofurans
Kilroy, Tim G.,Cozzi, Pier Giorgio,End, Nicole,Guiry, Patrick J.
, p. 1879 - 1888 (2007/10/03)
A series of thiophene- and benzothiophene-oxazoline containing ligands, were applied in the intermolecular asymmetric phenylation and cyclohexenylation of 2,3-dihydrofuran 1. Phenylation proceeded in moderate to high chemical yields, with good regioselectivities and in up to 95% ee. Cyclohexenylations gave similarly high chemical yields and regioselectivities with the optimal result being a 96% yield of the major product in 97% ee. 2,2-Dialkyl-2,3- dihydrofurans were also tested as substrates and the phenylation and cyclohexenylation of 2,2-dimethyl-2,3-dihydrofuran proceeded in high yields and ee's up to 91% and 89%, respectively. The phenylation and cyclohexenylation of the 2,2-diethyl analogue proceeded in excellent yields and ee's up to 99% and 87%, respectively. For each substrate, palladium complexes formed from the t-butyl-substituted ligand 10 gave the highest yields, regioselectivities, and enantioselectivities over the broad range of reaction conditions studied. 2,2-Diisopropyl-2,3-dihydrofuran was prepared but was found to be unreactive in the intermolecular Heck reaction thus providing insight into to the steric limits for 2,3-dihydrofuran substrates.
The Application of HETPHOX Ligands to the Asymmetric Intermolecular Heck Reaction
Kilroy, Tim G.,Cozzi, Pier Giorgio,End, Nicole,Guiry, Patrick J.
, p. 106 - 110 (2007/10/03)
Two new heterocyclic diphenylphosphinooxazolines derived from thiophene and benzothiophene were prepared in moderate to good yield and these, and a range of related HETPHOX ligands, were applied in the intermolecular asymmetric Heck reaction. Phenylation of 2,3-dihydrofuran with the t-butyl-substituted thiophene-oxazoline ligand gave (R)-2-phenyl-2,3-dihydrofuran highly regioselectively with excellent enantioselectivity (91-95% ee) and in good yields (70-97%). In addition, cyclohexenylation of 2,3-dihydrofuran proceeded with enantioselectivities of up to 97% ee in excellent (97%) yields, again with the t-butyl-substituted thiophene-oxazoline ligand proving optimal over a range of reaction conditions investigated.
Preparation of Novel Sulfur and Phosphorus Containing Oxazolines as Ligands for Asymmetric Catalysis
Allen, Joanne V.,Dawson, Graham J.,Frost, Christopher G.,Williams, Jonathan M. J.,Coote, Steven J.
, p. 799 - 808 (2007/10/02)
The preparation of enantiomerically pure ligands which contain both an oxazoline group and an additional sulfur or phosphorus donor atom are described.Methylthiomethyl, o-thioanisyl and thienyl oxazolines have been prepared in one step, and o-diphenylphosphinophenyl oxazolines have been prepared in two steps in good yields from commercially available starting materials.
Palladium-catalysed Asymmetric Allylic Substitution: a Ligand Design Incorporating Steric and Electronic Effects
Allen, Joanne V.,Coote, Steven J.,Dawson, Graham J.,Frost, Christopher G.,Martin, Christopher J.,Williams, Jonathon, M.
, p. 2065 - 2072 (2007/10/02)
Enantiomerically pure ligands containing a 4,5-dihydrooxazole moiety tethered to an auxiliary sulfur or phosphorus donor have been prepared.These ligands have been exploited for palladium-catalysed asymmetric allylic substitution, providing enantioselectivity in the catalytic reaction is discussed in terms of the steric and electronic influences provided by the ligand.
Enantioselective palladium catalysed allylic substitution with thienyl oxazoline ligands
Frost,Williams
, p. 2015 - 2018 (2007/10/02)
Homochiral thienyl oxazolines have been employed as ligands for enantioselective palladium catalysed allylic substitution. The ligands are straightforward to prepare in one step from commercially available materials and afford good levels of asymmetric induction in the catalytic allylic substitution process of up to 81% ee. The stereochemical outcome is described in terms of steric and electronic factors.
