187091-06-1Relevant academic research and scientific papers
A Unified and Desymmetric Approach to Chiral Tertiary Alkyl Halides
Huang, Zhongxing,Low, Kam-Hung,Zhang, Suihan,Zheng, Yin,Zi, Weiwei
, p. 1951 - 1961 (2022/02/09)
Enantioenriched tertiary alkyl halides are prevalent in bioactive molecules and can serve as versatile synthetic intermediates to construct complex structures. While conventional access to these motifs often hinges on stereoselective carbon-halogen or carbon-carbon bond formation reactions, desymmetric approaches using halogenated and prochiral tetrasubstituted carbons are largely elusive in comparison. Here, we report that a suite of dinuclear zinc catalysts with a prolinol- or pipecolinol-derived tetradentate ligand can reductively desymmetrize a large collection of easily available halomalonic esters to α-halo-β-hydroxyesters. These polyfunctionalized tertiary alkyl fluorides, chlorides, and bromides proved to be useful intermediates toward fluorinated drug analogs and polyhalogenated monoterpenes. The facile intramolecular epoxidation of the chiral chloride and bromide products has also enabled expeditious access to natural products containing tertiary alcohol motifs.
The nature of interaction between the carboxylate of substrates and the guanidinium moiety of Arg-145 in carboxypeptidase a probed by inhibitors of the enzyme
Kim, Dong H.,Park, Jeong-Il
, p. 2967 - 2970 (2007/10/03)
Replacement of the α-proton of 2-benzyl-3-hydroxypropanoic acid, a competitive inhibitor of carboxypeptidase A with a fluoro group brought about a 2-fold increase in K(i) value (0.61 mM → 1.19 mM), while pK(a) value decreased by 1.4 units (4.36 → 2.95), suggesting that the carboxylate of the inhibitor and that of substrates as well as hydrogen bonded to the guanidinium moiety of Arg-145 of the enzyme.
