90717-17-2Relevant articles and documents
Catalytic Asymmetric Acyloin Rearrangements of α-Ketols, α-Hydroxy Aldehydes, and α-Iminols by N, N′-Dioxide-Metal Complexes
Dai, Li,Li, Xiangqiang,Zeng, Zi,Dong, Shunxi,Zhou, Yuqiao,Liu, Xiaohua,Feng, Xiaoming
supporting information, p. 5041 - 5045 (2020/07/03)
A highly enantioselective acyloin rearrangement of cyclic α-ketols has been developed with a chiral Al(III)-N,N′-dioxide complex as catalyst. This strategy provided an array of optically active 2-acyl-2-hydroxy cyclohexanones in moderate to good yields with high enantioselectivities. The asymmetric isomerizations of acyclic α-hydroxy aldehydes and α-iminols were achieved as well under modified conditions, affording the corresponding chiral α-hydroxy ketones and α-amino ketones in moderate results. Moreover, further transformations of product to enantioenriched diols were carried out.
Expedient preparation of active pharmaceutical ingredient ketamine under sustainable continuous flow conditions
Kassin, Victor-Emmanuel H.,Gérardy, Romaric,Toupy, Thomas,Collin, DIégo,Salvadeo, Elena,Toussaint, Fran?ois,Van Hecke, Kristof,Monbaliu, Jean-Christophe M.
, p. 2952 - 2966 (2019/06/18)
A robust three-step continuous flow procedure is presented for the efficient and sustainable preparation of active pharmaceutical ingredient ketamine. The procedure relies on the main assets of continuous flow processing, starts from commercially available chemicals, utilizes low toxicity reagents and a FDA class 3 solvent under intensified conditions. The procedure features a unique hydroxylation step with molecular oxygen, a fast imination relying on triisopropyl borate and a thermolysis employing Montmorillonite K10 as a heterogeneous catalyst, all three steps being performed in ethanol. The three individual steps can be run independently or can be concatenated, thus providing a compact yet efficient setup for the production of ketamine. The scalability of the critical hydroxylation step was assessed in a commercial pilot continuous flow reactor. The process can also be adapted for the preparation of ketamine analogs. A thorough computational study on the backbone rearrangement of the cyclopentylphenylketone scaffold under thermal stress rationalizes the experimental selectivity and the various experimental observations reported herein.
