66405-16-1Relevant articles and documents
Direct Synthesis of Chiral NH Lactams via Ru-Catalyzed Asymmetric Reductive Amination/Cyclization Cascade of Keto Acids/Esters
Shi, Yongjie,Tan, Xuefeng,Gao, Shuang,Zhang, Yao,Wang, Jingxin,Zhang, Xumu,Yin, Qin
, p. 2707 - 2713 (2020/03/30)
Lactams with a stereogenic center adjacent to the N atom have existed in many medicinal agents and bioactive alkaloids. Herein we report a broadly applicable synthesis of enantioenriched NH lactams through a one-pot asymmetric reductive amination/cyclization sequence of easily available keto acids/esters. Such cascade processes alleviate the demand for protecting group manipulations as well as intermediate purification. This strategy is capable of constructing enantioenriched lactams and benzo-lactams of a five-, six-, or seven-membered ring in generally high yield and with excellent enantioselectivities (up to 97% ee). Scalable and concise syntheses of key drug intermediates have further displayed the importance of this methodology.
REACTION OF α,β-UNSATURATED ALDEHYDES WITH HYDROGEN PEROXIDE CATALYSED BY BENZENESELENINIC ACIDS AND THEIR PRECURSORS
Syper, Ludwik
, p. 2853 - 2872 (2007/10/02)
Oxidation of α,β-unsaturated aldehydes with hydrogen perixide catalysed by benzeneselenic acids and their precursors has been investigated.Bis 2-nitrophenyl diselenide has proved to be the most effective catalyst.The major products resulting from the oxidation are vinyl formates (a) which on hydrolysis give saturated aldehydes or ketones (g) having the carbon chain shortened by one carbon atom, compared with the starting aldehydes.The minor products are formyloxyoxiranes (b), α-hydroxycarbonyl (e) and α-formyloxycarbonyl (f) compounds with the carbon chain shortened by one carbon atom.Carbonyl compounds d, formally derived from an oxidative fission of the carbon-carbon double bond, have been also isolated.Diformyloxy (4c) and formyloxyacetoxy phenylmethane (5c) have been isolated when cinnamaldehyde (4) or 1-phenyl-2-formyloxypropane (5a) were oxidized, respectively.Possible mechanisms of formation of these products are discussed.Similar products resulted when α,β-unsaturated aldehydes were oxidized with organic peroxy acids.