Amplifying Reactivity of Metal Hydrides: A Heterotrimetallic NiAl2(μ2-H)2 Catalyst for the Facile Dearomatization of N-Heterocycles



Identifying methods to modulate the reactivity of metal-hydrides are lacking yet highly desirable given the role they play in a plethora of catalytic applications. Herein we report novel methodology to amplify reactivity of metal hydrides through the design of well-defined heterometallic bridged hydride species. Catalytic hydroboration of quinolines was dramatically altered by the addition of a secondary metal to bridge the Al-hydride species LAlH. Specifically, the addition of Ni(COD)2 led to the formation of novel heterotrimetallic species 1 which features Ni participating in 3-center- bonding with sterically accessible Al-H species and exhibits catalytic hydroboration of sterically encumbered quinolines and approximately a 400 times enhancement in catalytic reactivity in comparison to LAlH.


Supplementary material

Supplementary Information
Experimental procedures and analytical data for all compounds, detailed kinetics and substrate scope experiments, NMR spectra, crystallographic data, and structure refinement summary
Crystallographic Information File