158657-40-0Relevant articles and documents
Stereoselective Construction of γ-Lactams via Copper-Catalyzed Borylacylation
Bajohr, Jonathan,Lautens, Mark,Polishchuk, Iuliia,Torelli, Alexa,Whyte, Andrew
, p. 7915 - 7919 (2020/11/02)
A versatile and highly stereoselective borylative cyclization to generate polyfunctionalized γ-lactams has been developed. The stereoselective synthesis of these key ring systems is crucial due to their ubiquity in natural products. We report the diastero- and enantioselective construction of di- and trisubstituted γ-lactam cores, with examples containing an enantioenriched quaternary carbon.
Synthesis of Cyclic N-Hydroxylated Ureas and Oxazolidinone Oximes Enabled by Chemoselective Iodine(III)-Mediated Radical or Cationic Cyclizations of Unsaturated N-Alkoxyureas
Peilleron, Laure,Retailleau, Pascal,Cariou, Kevin
supporting information, p. 5160 - 5169 (2019/11/11)
In this study we describe the reactivity of unsaturated N-alkoxyureas in the presence of different combinations of a hypervalent iodine(III) reagent and a bromide source or TEMPO. Three complementary cyclizations can be achieved depending on the reaction conditions. On the one hand, PIFA with pyridinium bromide leads to an oxybromination reaction. On the other hand, bis(tert-butylcarbonyloxy)iodobenzene with tetrabutylammonium bromide or TEMPO triggers aminobromination or aminooxyamination reactions, respectively. Control experiments showed that the three reactions proceed through distinct mechanisms: the first process is ionic while the other two follow a radical manifold. (Figure presented.).
Iridium-catalyzed, asymmetric amination of allylic alcohols activated by lewis acids
Yamashita, Yasuhiro,Gopalarathnam, Apsara,Hartwig, John F.
, p. 7508 - 7509 (2008/02/11)
The direct, Ir-catalyzed, regio- and enantioselective amination of allylic alcohols with Lewis acid activators to form branched allylic amine products is reported. The reactions of arylamines, benzylic amines, and secondary aliphatic amines in the presence of Nb(OEt)5 as activator occurred with high regioselectivities and high enantioselectivities. These results led to the development of Ir-catalyzed reactions of allylic alcohol with arylamines and BPh3 as activator in catalytic amounts. These reactions are rare examples of enantioselective substitutions of allylic alcohols. They are particularly unusual examples of the substitution of allylic alcohols to generate branched substitution products from monosubstituted allylic alcohols and of enantioselective substitutions of allylic alcohols with amine nucleophiles. Copyright