Fig. 3: Scope of reaction with propargylic carbonates. | Nature Communications

Fig. 3: Scope of reaction with propargylic carbonates.

From: Trifluoroethanol-assisted asymmetric propargylic hydrazination to α-tertiary ethynylhydrazines enabled by sterically confined pyridinebisoxazolines

Fig. 3

Conditions A: α-aryl propargylic ester 1 (0.2 mmol), hydrazide 2 (0.24 mmol), CuCl2·2H2O (2.0 mol%), L9 (2.4 mol%), DABCO (0.2 mmol), CF3CH2OH (2.0 mL), –20 °C, 2 days. Conditions B: α-alkyl propargylic ester 1 (0.2 mmol), hydrazide 2 (0.24 mmol), CuBr2 (10 mol%), L8 (12 mol%), DABCO (0.1 mmol), CF3CH2OH (2.0 mL), –20 °C, 2 days. Conditions C: propargylic ester 1 (0.2 mmol), hydroxylamine 6 (0.24 mmol), CuBr2 (10 mol%), L8 (12 mol%), N,N-dimethylpiperazine (0.8 mmol), nPrOH (2.0 mL), –20 °C, 4 days. Isolated yield. The e.e values were determined by chiral HPLC analysis. The absolute configuration of (S)−3e and (R)−3r was determined by X-ray analysis, for detail see Section 10 of the SI.

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