Related Experiment Video
Updated: Dec 28, 2025

Metal-free Synthesis of Ynones from Acyl Chlorides and Potassium Alkynyltrifluoroborate Salts
Published on: February 24, 2015
A Room-Temperature Stable Y(II) Aryloxide: Using Steric Saturation to Kinetically Stabilize Y(II) Complexes
Samuel A Moehring1, Matthias Miehlich2, Christopher J Hoerger2
1Department of Chemistry, University of California, Irvine, California 92697-2025, United States.
Abstract:
The utility of the bulky aryloxide ligands 2,6-Ad2-4-Me-C6H2O- (Ad,Ad,MeArO-) and 2,6-Ad2-4-t-Bu-C6H2O- (Ad,Ad,ArO-; Ad = 1-adamantyl) for stabilizing the Y(II) ion is reported and compared with the results with 2,6-t-Bu2-4-Me-C6H2O- (Ar'O-). In contrast to the reduction product obtained from reducing Y(OAr')3 with potassium graphite, which is only stable in solution for 60 s at room temperature, KC8 reduction of Y(OArAd,Ad,)3 in THF in the presence of 2.2.2-cryptand (crypt) produces the room-temperature stable, crystallographically characterizable Y(II) aryloxide [K(crypt)][Y(OArAd,Ad,)3]. The X-band EPR spectrum at 77 K shows an axial pattern with resonances centered at g⊥ = 1.97 and g∥ = 2.00 and hyperfine coupling constants of A⊥ = 156.5 G and A∥ = 147.8 G and at room temperature shows an isotropic pattern with giso = 1.98 and Aiso = 153.3 G, which is consistent with an S = 1/2 spin system with nuclear spin I = 1/2 for the 89Y isotope (100% natural abundance).
Related Concept Videos
Alkynes to Aldehydes and Ketones: Hydroboration-Oxidation
One of the convenient methods for the preparation of aldehydes and ketones is via hydration of alkynes. Hydroboration-oxidation of alkynes is an indirect hydration reaction in which an alkyne is treated with borane followed by oxidation with alkaline peroxide to form an enol that rapidly converts into an aldehyde or a ketone. Terminal alkynes form aldehydes, whereas internal alkynes give ketones as the final product.
Radical Reactivity: Steric Effects
Along with electronic...
Nucleophilic Aromatic Substitution of Aryldiazonium Salts: Aromatic SN1
In the Sandmeyer reaction, for example, the diazonio group is replaced by a chloro, bromo,...
Aldehydes and Ketones to Alkenes: Wittig Reaction Overview
Types of Enols and Enolates
Aryldiazonium Salts to Azo Dyes: Diazo Coupling

