159813-00-0Relevant articles and documents
Catalytic Enantioselective Synthesis of Morpholinones Enabled by Aza-Benzilic Ester Rearrangement
He, Yu-Ping,Wu, Hua,Wang, Qian,Zhu, Jieping
, p. 7320 - 7325 (2021)
Chiral morpholinone is an important building block in organic synthesis and a pharmacophore in medicinal chemistry. However, catalytic enantioselective methods for the construction of this N,O-heterocycle remain scarce. We report herein a chiral phosphoric acid-catalyzed enantioselective synthesis of C3-substituted morpholinones from aryl/alkylglyoxals and 2-(arylamino)ethan-1-ols. The reaction proceeds through a domino [4 + 2] heteroannulation followed by a 1,2-aryl/alkyl shift of the resulting cyclic α-iminium hemiacetals. It represents formally an unprecedented asymmetric aza-benzilic ester rearrangement reaction. A concise synthesis of L-742,694, a neurokinin-1 receptor antagonist, featuring this reaction is documented.
Stereoselective synthesis of 2-(S)-(3,5-bis(trifluoromethyl) benzyloxy)-3-(S)-phenyl-1,4-oxazine
Ashwood, Michael S.,Cottrell, Ian F.,Davies, Antony J.
, p. 957 - 963 (2007/10/03)
A convenient process for the preparation of the secondary amine 6, 2-(S)-(3,5-bis(trifluoromethyl)benzyloxy)-3-(S)- (3,5-bis(trifluoromethyl)benzyloxy)-3-(S)-phenyl-1,4-oxazine, is described starting from the readily available (S)-phenylglycine 1. The process features efficient construction of the homochiral oxazinone intermediate 3 and stereoselective introduction of the 2-(3,5-bis(trifluoromethyl)-benzyloxy) group by L-Selectride reduction followed by in situ alkylation with the highly reactive 3,5-bis(trifluoromethyl)-benzyl triflate 4.
