Guanghui Deng

Highly Enantio- and Diastereoselective Mannich Reactions of Chiral Ni(II) Glycinates with Amino Sulfones. Efficient Asymmetric Synthesis of Aromatic α,β-Diamino Acids

This paper describes a practical, enantio- and diastereoselective Mannich reaction between a chiral Ni(II) complex of glycine 1 and alpha-amino sulfones 2, involving the creation of a carbon-carbon bond and two stereogenic centers in a single operation; it represents an attractive route to the synthesis alpha,beta-diamino acids.

Design, synthesis and biological evaluation of hetero-aromatic moieties substituted pyrrole-2-carbonitrile derivatives as dipeptidyl peptidase IV inhibitors.

A series of novel hetero-aromatic moieties substituted α-amino pyrrole-2-carbonitrile derivatives was designed and synthesized based on structure-activity relationships (SARs) of pyrrole-2-carbonitrile inhibitors. All compounds demonstrated good dipeptidyl peptidase IV (DPP4) inhibitory activities (IC50 = 0.004-113.6 μM). Moreover, compounds 6h (IC50 = 0.004 μM) and 6n (IC50 = 0.01 μM) showed excellent inhibitory activities against DPP4, good selectivity (compound 6h, selective ratio: DPP8/DPP4 = 450.0; DPP9/DPP4 = 375.0; compound 6n, selective ratio: DPP8/DPP4 = 470.0; DPP9/DPP4 = 750.0) and good efficacy in an oral glucose tolerance test in ICR mice. Furthermore, compounds 6h and 6n demonstrated moderate PK properties (compound 6h, F% = 37.8%, t1/2 = 1.45 h; compound 6n, F% = 16.8%, t1/2 = 3.64 h).

Efficient Synthesis of α-Aryl-/Heteroaryl-Substituted β-Amino Acids via Ni(II) Complex through the Suzuki Coupling Reaction

We described a synthesis method by first using chlorotrimethylsilane as the activator to brominate the Ni(II) complex of the beta-alanine Schiffs base [beta-AlaNi(II)PABA] 1 and developed it to prepare beta-amino acids 5. The procedure involves a Suzuki coupling reaction between boric acids and the bromoenone 2, followed by hydrogenation and hydrolysis. This is the first report of the application of the Ni (II) complex [beta-AlaNi(II)PABA], which represents an attractive route to afford alpha-aryl-/heteroaryl-substituted beta-amino acids.

Synthesis and biological evaluation of pyrrolidine-2-carbonitrile and 4-fluoropyrrolidine-2-carbonitrile derivatives as dipeptidyl peptidase-4 inhibitors for the treatment of type 2 diabetes.

A novel series of pyrrolidine-2-carbonitrile and 4-fluoropyrrolidine-2-carbonitrile derivatives was designed, synthesized, and found to act as dipeptidyl peptidase-4 (DPP-4) inhibitors. From this series of compounds, compound 17a was identified as an efficacious, safe, and selective inhibitor of DPP-4. In vivo studies in ICR and KKAy mice showed that administration of this compound resulted in decreased blood glucose in these mice after an oral glucose challenge. Compound 17a showed high DPP-4 inhibitory activity (IC(50)=0.017 μM), moderate selectivity against DPP-4 (selective ratio: DPP-8/DPP-4=1324; DPP-9/DPP-4=1164), and good efficacy in oral glucose tolerance tests in ICR and KKAy mice. These in vivo anti-diabetic properties and its desirable pharmacokinetic profile in Sprague-Dawley rats demonstrate that compound 17a is a promising candidate for development as an anti-diabetic agent.

Efficient Synthesis of Symmetrical α,α-Disubstituted β-Amino Acids and α,α-Disubstituted Aldehydes via Dialkylation of Nucleophilic β-Alanine Equivalent

Homologation of the nucleophilic beta-alanine equivalent beta-Ala Ni(II)-PABP [Ni(II) complex of beta-alanine Schiff base with 2-[N-(alpha-picolyl)amino]benzophenone (PABP), 1] via alkyl halide alkylation was systematically studied as a general method for preparing symmetrically alpha,alpha-disubstituted beta-amino acids. The dialkylation reactions could be easily performed and did not require inert atmosphere, dried solvents, and low temperatures, thereby affording the benefits of operationally convenient experimental procedure and high atom economy. Further, the methodology developed by us can also be used to generate symmetrical alpha,alpha-disubstituted aldehydes through an alternative decomposition method.