49745-68-8Relevant articles and documents
An Iridium Catalytic System Compatible with Inorganic and Organic Nitrogen Sources for Dual Asymmetric Reductive Amination Reactions
Chang, Mingxin,Gao, Zhaofeng,Geng, Huiling,Huang, Haizhou,Liu, Jingwen
supporting information, p. 27307 - 27311 (2021/11/17)
Asymmetric reductive amination (ARA) is one of the most promising methods for the synthesis of chiral amines. Herein we report our efforts on merging two ARA reactions into a single-step transformation. Catalyzed by a complex formed from iridium and a steric hindered phosphoramidite, readily available and inexpensive aromatic ketones initially undergo the first ARA with ammonium acetate to afford primary amines, which serve as the amine sources for the second ARA, and finally provide the enantiopure C2-symmetric secondary amine products. The developed process competently enables the successive coupling of inorganic and organic nitrogen sources with ketones in the same reaction system. The Br?nsted acid additive plays multiple roles in this procedure: it accelerates the formation of imine intermediates, minimizes the inhibitory effect of N-containing species on the iridium catalyst, and reduces the primary amine side products.
Derivatized polyhydroxystyrenes with a novolak type structure and processes for preparing the same
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Page/Page column 3, (2008/12/07)
A process for preparing derivatized poly(4-hydroxystryrene) having a novolak type structure which comprises the steps of (i) supplying a solution of methanol containing 4-hydroxyphenylmethylcarbinol, (ii) subjecting said solution to an acid catalyzed displacement reaction for a sufficient period of time and under suitable conditions of temperature and pressure to convert substantially all of said carbinol to 4-hydroxyphenylmethylcarbinol methyl ether in solution, (iii) polymerizing said ether containing solution in the presence of a suitable acid catalyst for a sufficient period of time and under suitable conditions of temperature and pressure to form a novolak type polymer. New compositions of matter which comprise the derivatized poly(4-hydroxystyrene) prepared in the above manner and which have application in the electronic chemicals market such as in a photoresist composition, and in other areas such as in varnishes, printing inks, epoxy resins, copying paper, tackifiers for rubber, crude oil separators, and the like.
Synthesis of polysubstituted bicyclo[3.3.1]nonane-3,7-diones from cyclohexa-2,5-dienones and dimethyl 1,3-acetonedicarboxylate
Camps, Pelayo,González, Albert,Mu?oz-Torrero, Diego,Simon, Montserrat,Zú?iga, Adriana,Martins, Miriam A.,Font-Bardia, Mercè,Solans, Xavier
, p. 8141 - 8151 (2007/10/03)
Oxidation of polysubstituted phenols with phenyliodonium diacetate gives cyclohexa-2,5-dienones, which on reaction with dimethyl 1,3-acetonedicarboxylate afford double-Michael-addition derivatives, whose hydrolysis and decarboxylation provides polysubstituted bicyclo[3.3.1]nonane-3,7-diones. For steric and/or electronic reasons, the Michael reaction only works with 3,5-unsubstituted or 3-substituted cyclohexa-2,5-dienones, if the substituent is not an electron-releasing or a good electron-withdrawing group. Hydrolysis and decarboxylation of the double-Michael adducts from 2,4,4- or 2,4,4,6-substituted cyclohexa-2,5-dienones gives only products of partial hydrolysis and decarboxylation, which exist exclusively in the enol form. (C) 2000 Elsevier Science Ltd.
