The preparation of ester heterocycles mostly uses heteroatoms as nucleophilic sites, which are achieved by intramolecular substitution or addition reactions. Compound: (S)-Propane-1,2-diamine dihydrochloride( cas:19777-66-3 ) is researched.COA of Formula: C3H12Cl2N2.Park, Jae-Hoon; Ha, Hyun-Joon; Lee, Won Koo; Genereux-Vincent, Tobie; Kazlauskas, Romas J. published the article 《Molecular Basis for the Stereoselective Ammonolysis of N-Alkyl Aziridine-2-Carboxylates Catalyzed by Candida antarctica Lipase B》 about this compound( cas:19777-66-3 ) in ChemBioChem. Keywords: mol modeling stereoselective ammonolysis aziridinecarboxylate catalyst Candida antarctica lipase. Let’s learn more about this compound (cas:19777-66-3).
Candida antarctica lipase B was used to catalyzed a stereoselective ammonolysis of N-(alkyl)aziridine-2-carboxylates in tert-butanol with ammonia and yielded (2S)-2-aziridinecarboxamide and remaining (2R)-2-aziridinecarboxylic acid ester. Varying the N-1 substituent on the aziridine ring changed the rate and stereoselectivity of the reaction. Substrates with a benzyl substituent or a (1R)-1-phenylethyl substituent reacted approx. ten times faster than substrates with a (1S)-1-phenylethyl substituent. Substrates with a benzyl substituent showed little stereoselectivity (E = 5-7) while substrates with either a (1R)-1-phenylethyl or (1S)-1-phenylethyl substituent showed high stereoselectivity (D > 50). Mol. modeling by using the current paradigm for enantioselectivity-binding of the slow enantiomer by an exchange-of-substituents orientation-could not account for the exptl. results. However, modeling an umbrella-like-inversion orientation for the slow enantiomer could account for the exptl. results. Steric hindrance between a Me group in the (1S)-1-phenylethyl substituent and Thr138 and Ile189 in the acyl-binding site likely accounts for the slow reaction. Enantioselectivity likely stems from an unfavorable interaction of the methine hydrogen with Thr40 for the slow enantiomer and from subtle differences in the orientations of the other three substituents. This success in rationalizing the enantioselectivity supports the notion that an umbrella-like-inversion orientation can contribute to enantioselectivity in lipases.
There are many compounds similar to this compound(19777-66-3)COA of Formula: C3H12Cl2N2. if you want to know more, you can check out my other articles. I hope it will help you，maybe you’ll find some useful information.
Reference:
Quinoxaline – Wikipedia,
Quinoxaline | C8H6N2 | ChemSpider