Organic Chemistry Portal

Abstracts

Search:

Nickel-Catalyzed Deaminative Allenylation of Amino Acid Derivatives: Catalytic Activity Enhanced by an Amide-Type NN2 Pincer Ligand

Xingjie Zhang*, Chenchen Jiao, Di Qi, Xiaopan Liu, Zhiguo Zhang and Guisheng Zhang*

*School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan 453007, China, Email: zhangxingjiehtu.edu.cn, zgshtu.cn

X. Zhang, C. Jiao, D. Qi, X. Liu, Z. Zhang, G. Zhang, Org. Lett., 2022, 24, 5361-5365.

DOI: 10.1021/acs.orglett.2c02042


see article for more reactions

Abstract

A well-designed, electron deficient, and sterically hindered amide-type NN2 pincer ligand was crucial to the success of a general, efficient, and practical nickel-catalyzed deaminative allenylation of amino acid derivatives with terminal alkynes under mild conditions. The reaction offers good scalability, broad substrate scope, and functional group tolerance.


see article for more examples


proposed mechanism



General procedure for deaminative allenylation of amino acid derivatives

In a nitrogen-filled glovebox, NiCl26H2O (0.03 mmol, 7.1 mg), ligand (0.03 mmol, 8.9 mg), anhydrous K3PO4 (0.39 mmol, 82.8 mg), pyridinium salt (0.3 mmol) and N,N-dimethylformamide (1.5 mL) were successively added to an oven-dried sealable Schlenk tube (10.0 mL) fitted with a stir bar. Then terminal alkyne (0.45 mmol) was added via a microliter syringe (If terminal alkyne is a solid, it was added before the solvent). The tube was securely sealed and taken outside the glovebox. After stirring at 20C for 12 h, the reaction mixture was diluted with ethyl acetate and quenched with water. The aqueous layer was extracted with ethyl acetate. The combined organic extracts were washed with water and brine, and dried over anhydrous Na2SO4. The resulting filtrate was concentrated under vacuum and the residue was purified by column chromatography on silica gel to afford the desired product.


Key Words

allenes


ID: J54-Y2022