3338-00-9Relevant articles and documents
Chemoenzymatic Synthesis of Substituted Azepanes by Sequential Biocatalytic Reduction and Organolithium-Mediated Rearrangement
Zawodny, Wojciech,Montgomery, Sarah L.,Marshall, James R.,Finnigan, James D.,Turner, Nicholas J.,Clayden, Jonathan
supporting information, p. 17872 - 17877 (2019/01/04)
Enantioenriched 2-aryl azepanes and 2-arylbenzazepines were generated biocatalytically by asymmetric reductive amination using imine reductases or by deracemization using monoamine oxidases. The amines were converted to the corresponding N′-aryl ureas, which rearranged on treatment with base with stereospecific transfer of the aryl substituent to the 2-position of the heterocycle via a configurationally stable benzyllithium intermediate. The products are previously inaccessible enantioenriched 2,2-disubstituted azepanes and benzazepines.
The reaction of cyclic imines with the Ruppert-Prakash reagent. Facile approach to α-trifluoromethylated nornicotine, anabazine, and homoanabazine
Shevchenko, Nikolay E.,Vlasov, Katja,Nenajdenko, Valentine G.,R?schenthaler, Gerd-Volker
scheme or table, p. 69 - 74 (2011/02/27)
We have demonstrated that the Ruppert-Prakash reagent is able to react with a number of cyclic imines under acidic condition to afford the corresponding α-trifluoromethyl derivatives of nitrogen heterocycles. 5-7-Membered cyclic imines bearing various alkyl, aryl or heterocyclic group were successfully involved in this transformation. Novel trifluoromethylated analogues of nicotine, anabasine, and homoanabasine alkaloids were synthesized.
Oxidative C-arylation of free (NH)-heterocycles via direct (sp3) C-H bond functionalization
Sezen, Bengue,Sames, Dalibor
, p. 13244 - 13246 (2007/10/03)
The development of a new chemical transformation, namely oxidative C-arylation of saturated (NH)-heterocycles, is described. This reaction combines dehydrogenation and arylation in one process, leading to cross-coupling of (NH)-heterocycles and haloarenes. Typical reaction conditions involve heating the reaction partners in anhydrous dioxane at 120-150 °C in the presence of RhCl(CO)[P(Fur)3]2 as the catalyst and Cs2CO3 as the base. Addition of tert-butylethylene as the hydrogen acceptor increases the chemical yield by diminishing the dehalogenation pathway. This method demonstrated a good substrate scope, allowing for cross-coupling of a variety of (NH)-heterocycles (e.g., pyrrolidine, piperidine, piperazine, morpholine) and halo(hetero)arenes to afford valuable heterocyclic products in one step. The preliminary mechanistic studies provided some insight regarding the key events in the proposed catalytic cycle, including β-hydride elimination of an amido rhodium complex and carbometalation of the resulting imine. A large kinetic isotope effect [KIE (kC-H/kC-D) = 4.3] suggests that one or both β-hydride elimination steps are rate determining. The central role for the phosphine ligand was established in controlling the partitioning between the oxidative C-arylation and N-arylation pathways. Copyright
