In this context, the chemical community has become increasingly aware of the power of dynamic kineRc asymmetric transformaRons (DyKAT) that can be used to deliver compounds containing one or mulRple defined stereogenic elements with high stereocontrol. In such reacRon processes, diastereoisomeric interconversion of intermediates or starRng materials, combined with subsequent preferenRal reacRon of one diastereoisomer, can lead to enhanced product stereoselecRvity. Since the term DyKAT was introduced by Trost in 2000, 36 a plethora of applicaRons of this strategy has been developed and recognised, and this area has been extensively reviewed. Four subtypes (I to IV) of DyKAT have been categorised, observed, and developed to date, that either involve the deracemizaRon of enanRomers through diastereoisomeric intermediates (types I and II) or the de-epimerizaRon of diastereoisomers (types III and IV). In type III and IV systems, diastereoisomer interconversion is harnessed alongside a (usually catalyst controlled) selecRve reacRon that results in stereoisomeric resoluRon and determines the relaRve and absolute configuraRon within the desired product stereoisomer. A representaRve example of a DyKAT type III process is exemplified schemaRcally in Figure . In this case epimerizaRon of both stereogenic centres within the 1,4-diol substrate are promoted by reversible (de)hydrogenaRon using the Ru-catalyst, that is followed by consecuRve enanRoselecRve acylaRons, allowing the selecRve generaRon of the (R,R)-6 in 95% yield, 92:8 dr and >99:1 er from a 50:50 mixture of racemic and meso-starRng materials. Building upon these principles and the growing impact of organocatalysis in the pharmaceuRcal industry, in this manuscript an effecRve syntheRc strategy for the preparaRon of funcRonalised β-hydroxyβ-pyrazolone amides in high dr and er (up to >95:5 dr, >99:1 er) is described. Given that nitrogen-containing heterocycles are incorporated into an array of biologically relevant compounds, and with pyrazole derivaRves a prevalent heterocycle of widespread relevance, the generaRon of catalyRc enanRoselecRve methods that would lead to chiral pyrazolone heterocycle derivaRves was targeted. The developed process combines an isothiourea-mediated highly enanRoselecRve formal [2+2]-cycloaddiRon of C(1)-ammonium enolates to generate diastereoisomeric spirocyclic β-lactones, coupled with a subsequent substrate-controlled DyKAT type III process where the absolute configuraRon at C(3) within the β-lactone is labile and that at C(4) is fixed (Figure ). Although the [2+2]-cycloaddiRon proceeds with high enanRoselecRvity (typically 99:1 er), only moderate diastereoselecRvity is observed upon β-lactone isolaRon (typically ≈ 70:30 dr) presumably due to facile epimerisaRon. However, in situ ring-opening of this diastereoisomeric mixture with a nucleophile generates funcRonalised β-hydroxy-β-pyrazolones exhibiRng excepRonal diastereocontrol (up to >95:5 dr). MechanisRc and DFT analysis is consistent with a post-catalysis DyKAT type III process leading to the observed enhanced stereoselecRvity (products in up to 98% yield, >95:5 dr, >99:1 er).