An enantioselective hydrogenation of fluorinated hydrazones has been achieved by employing [Pd(R)-DTBM-SegPhos(OCOCF3)(2)] as the catalyst, providing a general and convenient method toward chiral fluorinated hydrazines. A broad substrate scope including beta-aryl-, gamma-aryl-, and alkyl-chain-substituted hydrazones worked efficiently in high yields and up to 94% of enantioselectivity. The reductive amination between trifluoromethyl-substituted ketones and benzohydrazides could also proceed smoothly.
Highly Efficient Synthesis of Chiral α-CF<sub>3</sub> Amines via Rh-Catalyzed Asymmetric Hydrogenation
作者:Jun Jiang、Wenxin Lu、Hui Lv、Xumu Zhang
DOI:10.1021/acs.orglett.5b00087
日期:2015.3.6
Highly enantioselective catalyticasymmetrichydrogenation of α-CF3-enamides has been achieved by employing rhodium–DuanPhos as the catalyst, which provides a readily accessible method for the synthesis of chiral trifluoromethylated amines. The reaction has a broad substrate scope; both aryl- and alkyl-substituted α-CF3-enamides worked smoothly and afford the corresponding chiral amines in high yields
Access to substituted trifluoromethyl ketones using the versatile synthetic intermediate ( E )-1,1-dimethyl-2-(1,1,1-trifluoropropan-2-ylidene)hydrazine
作者:Ted C. Judd、Derek B. Brown
DOI:10.1016/j.tetlet.2017.10.022
日期:2017.11
ketones and aldehydes, as well as palladium-catalyzed cross-couplings with aryl bromides. Mild hydrolysis of the N,N-dimethylhydrazone products from these transformations affords the corresponding trifluoromethyl ketones in good to excellent yields.