5279-14-1Relevant articles and documents
Unanticipated Silyl Transfer in Enantioselective α,β-Unsaturated Acyl Ammonium Catalysis Using Silyl Nitronates
Matviitsuk, Anastassia,Greenhalgh, Mark D.,Taylor, James E.,Nguyen, Xuan B.,Cordes, David B.,Slawin, Alexandra M. Z.,Lupton, David W.,Smith, Andrew D.
supporting information, p. 335 - 339 (2020/01/11)
The use of silyl nitronates is reported for the isothiourea-catalyzed synthesis of ?3-nitro-substituted silyl esters containing up to two contiguous stereocenters in good yields with excellent enantioselectivities (up to 93% yield and 99:1 er). The serendipitously discovered formation of silyl ester products in this reaction demonstrates a novel platform for catalyst turnover in α,β-unsaturated acyl ammonium catalysis.
NITRATED HYDROCARBONS, DERIVATIVES, AND PROCESSES FOR THEIR MANUFACTURE
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Page/Page column 30-31, (2009/12/02)
Provided is a process for the formation of nitrated compounds by the nitration of hydrocarbon compounds with dilute nitric acid. Also provided are processes for preparing industrially useful downstream derivatives of the nitrated compounds, as well as novel nitrated compounds and derivatives, and methods of using the derivatives in various applications.
Nitroalkylation of Aromatic Hydrocarbons Promoted by Manganese(III) Acetate
Kurz, Michael E.,Ngoviwatchai, Preecha,Tantrarant, Tosaporn
, p. 4668 - 4672 (2007/10/02)
Additional mechanistic and synthetic details concerning the formation of nitroalkylated aromatic products from the reaction of nitroalkans with manganese(III) acetate and an aromatic compound are presented.A large isotope effect (kH/kD = 4.02-4.20) was found for both manganese(III)- and cerium(IV)-promoted nitromethylations with nitromethane-d3 while no isotope effect (kH/kD = 1.05) was observed with benzene-d6.This indicated that deprotonation (most likely from an aci radical cation) to the nitromethyl radical is the slow step while subsequent rearomatization of a ?-radical complex occurs rapidly.Somewhat more convenient methods of activating the manganese(III) acetate promoter were found.However, attempts to find cooxidants or other additives which could improve this process met with only limited success.The reaction of either toluene or benzene with nitroethane or the nitropropanes and manganese(III) acetate in refluxing acetic acid gave much poorer yields (3-8percent) of the corresponding nitroalkylated products.Incorporation of sodium acetate into these systems completely eliminated the aromatic substitution products and formed α-nitroalkyl acetates instead.Implications of this finding on the mechanism for the generation of nitroalkyl radicals are discussed.
