622830-41-5Relevant articles and documents
A chiral analog of the bicyclic guanidine TBD: Synthesis, structure and Br?nsted base catalysis
Goldberg, Mariano,Sartakov, Denis,Bats, Jan W.,Bolte, Michael,G?bel, Michael W.
, p. 1870 - 1876 (2016/10/05)
Starting from (S)-β-phenylalanine, easily accessible by lipase-catalyzed kinetic resolution, a chiral triamine was assembled by a reductive amination and finally cyclized to form the title compound 10. In the crystals of the guanidinium benzoate salt the six membered rings of 10 adopt conformations close to an envelope with the phenyl substituents in pseudo-axial positions. The unprotonated guanidine 10 catalyzes Diels-Alder reactions of anthrones and maleimides (25-30% ee). It also promotes as a strong Br?nsted base the retro-aldol reaction of some cycloadducts with kinetic resolution of the enantiomers. In three cases, the retroaldol products (48-83% ee) could be recrystallized to high enantiopurity (≥95% ee). The absolute configuration of several compounds is supported by anomalous X-ray diffraction and by chemical correlation.
Development of a commercial process for (S)-β-phenylalanine (1)
Grayson, J. Ian,Roos, Juergen,Osswald, Steffen
, p. 1201 - 1206 (2011/12/16)
The development of a commercial manufacturing route for (S)-β-phenylalanine 8, a key pharmaceutical building block, is described. The different approaches which were investigated, based on catalytic asymmetric hydrogenation of enamide intermediates and on biocatalysis using acylase and lipase hydrolyses, are compared. The lipase resolution route was chosen for scale-up, and the final two-step process, based on readily available raw materials, is shown to be robust at full manufacturing scale
