Enantioselective Michael Addition of 1,3-dicarbonyl Compounds to Nitroalkenes Catalyzed by Nickel(II)-Diamine Complexes: Reaction and Mechanism
Document Type
Thesis
Degree Name
Master of Science (MS)
Department
Chemistry
Date of Award
9-1-2026
Abstract
In this work, chiral Ni(II)-diamine complexes catalyze the enantioselective Michael addition of different malonates to a range of nitroalkene substrates obtained from nitroisoxazole. Three catalyst systems were assessed: Ni(II)-bis[(R,R)-N,N′-dibenzylcyclohexane-1,2 diamine]Br₂ (Catalyst A), the corresponding NiCl₂ complex (Catalyst B), and a complex formed from Ni(OAc)₂ (Catalyst C). Isopropanol was found to be the ideal medium with Catalyst C providing highest yield and enantiomeric excess (ee) at room temperature, according to a methodical solvent optimization study across 14 reaction conditions. The maximum ee of 99% found in this investigation was obtained by combining Catalyst C with isopropanol. High facial selectivity is imposed by a dual-activation mechanism in which the nickel center coordinates the nitroalkene electrophile and the malonate enolate nucleophile within the chiral diamine pocket. This study offers a useful, safe, and scalable pathway to enantioenriched Michael adducts with the therapeutically useful nitroisoxazole scaffold.
Advisor
Bukuo Ni
Subject Categories
Chemistry | Physical Sciences and Mathematics
Recommended Citation
Mohsin, Usoshi, "Enantioselective Michael Addition of 1,3-dicarbonyl Compounds to Nitroalkenes Catalyzed by Nickel(II)-Diamine Complexes: Reaction and Mechanism" (2026). Electronic Theses & Dissertations. 1400.
https://lair.etamu.edu/etd/1400
