82729-98-4Relevant articles and documents
Amine Transaminase Engineering for Spatially Bulky Substrate Acceptance
Wei?, Martin S.,Pavlidis, Ioannis V.,Spurr, Paul,Hanlon, Steven P.,Wirz, Beat,Iding, Hans,Bornscheuer, Uwe T.
, p. 1022 - 1026 (2017/06/13)
Amine transaminase (ATA) catalyzing stereoselective amination of prochiral ketones is an attractive alternative to transition metal catalysis. As wild-type ATAs do not accept sterically hindered ketones, efforts to widen the substrate scope to more challenging targets are of general interest. We recently designed ATAs to accept aromatic and thus planar bulky amines, with a sequence-based motif that supports the identification of novel enzymes. However, these variants were not active against 2,2-dimethyl-1-phenyl-propan-1-one, which carries a bulky tert-butyl substituent adjacent to the carbonyl function. Here, we report a solution for this type of substrate. The evolved ATAs perform asymmetric synthesis of the respective R amine with high conversions by using either alanine or isopropylamine as amine donor.
Enantioselective synthesis of protected amines by the catalytic asymmetric addition of hydrazoic acid to ketenes
Dai, Xing,Nakai, Takashi,Romero, Jan A. C.,Fu, Gregory C.
, p. 4367 - 4369 (2008/03/12)
(Chemical Equation Presented) A-mine of possibilities: An effective method for the conversion of achiral ketenes into enantioenriched protected amines was developed by tuning the structure and reactivity of a catalyst on the basis of a mechanistic hypothe
Enantioselective synthesis of primary 1-(aryl)alkylamines by nucleophilic 1,2-addition of organolithium reagents to hydroxyoxime ethers and application to asymmetric synthesis of G-protein-coupled receptor ligands
Atobe, Masakazu,Yamazaki, Naoki,Kibayashi, Chihiro
, p. 5595 - 5607 (2007/10/03)
(E)-Arylaldehyde oxime ethers bearing a (1S)-2-hydroxy-1-phenylethyl or (2R)-1-hydroxy-2-phenylethyl group as a chiral auxiliary, both derived from a single precursor, methyl (R)-mandelate, underwent nucleophilic addition with organolithium reagents via six-membered chelates to give the diastereomerically enriched (R)- and (S)-adducts, respectively, which, after chiral auxiliary removal by reductive N-O bond cleavage, led to the corresponding (R)- and (S)-1-(aryl)ethylamines. This organolithium addition protocol using methyllithium was applied in an enantiodivergent fashion to the preparation of both enantiomers of 1-(2-hydroxyphenyl)ethylamine, which has been previously used as an efficient chiral auxiliary for the synthesis of natural products in this laboratory. The synthetic utility of this methodology involving diastereoselective methyl addition was demonstrated by further application to the asymmetric synthesis of a new type of calcium receptor agonist (calcimimetics), (R)-(+)-NPS R-568 and its thio analogue. Furthermore, diastereoselective vinylation was accomplished by application of the hydroxy oxime ether-based protocol using vinyllithium, which allowed the development of the enantioselective synthesis of the NK-1 receptor antagonists, (+)-CP-99,994 and (+)-CP-122,721.
Asymmetric synthesis of α-branched primary amines on solid support via novel hydrazine resins
Enders, Dieter,Kirchhoff, Jan H.,Koebberling, Johannes,Peiffer, Thomas H.
, p. 1241 - 1244 (2007/10/03)
Matrix presented Two novel chiral hydrazine resins for asymmetric solid-phase synthesis have been developed. The enantiopure β-methoxyamino auxiliaries, derived from frans-4-hydroxy-(S) -proline and (R) -leucine, were attached to Merrifield resin and transformed into their corresponding hydrazines. Immobilization of various aldehydes, followed by 1,2-addition of organolithium reagents to the resulting enantiopure hydrazones and reductive cleavage from the solid support, furnished α-branched amines, which were isolated as their corresponding amides in good overall yields and enantiomeric excesses of up to 86%.
Application of New Camphor-Derived Mercapto Chiral Auxiliaries to the Synthesis of Optically Active Primary Amines
Yang, Teng-Kuei,Chen, Ruey-Yuan,Lee, Dong-Sheng,Peng, Wen-Shiuan,Jiang, Yao-Zhong,et al.
, p. 914 - 921 (2007/10/02)
A series enantiomerically pure sulfinimines carrying new camphor-based mercapto chiral auxiliaries are subjected to assymetric alkylation.Such reaction offers an excellent route to the preparation of optically active primary amines.Also reported here is an unprecedented Grignard addition of a chiral sulfenimine leading to a single enantiomer of the corresponding sulfenamide and thence produced enantiopure amine after acidic aqueous workup.The chiral auxiliary can be recovered in high yield.
