Synthesis of 7-azabicyclo[2.2.1]heptane-1-carboxylate via silver/ThioClickFerrophos-catalyzed asymmetric 1,3-dipolar cycloaddition of dihydropyrrole ester with N-substituted maleimide

Recent Advances of Catalytic Asymmetric 1,3-Dipolar Cycloadditions

“…Prompted by this research, chiral ferrocenyl P , S -ligands, such as 177 and 178 , have been developed to date by other groups (Scheme ). − Use of these two ligands in combination with AgOAc was revealed to promote the 1,3-DC with acyclic enones in an endoselective manner, which is in contrast with Carretero’s exoselective reaction. , …”

Silver-Catalyzed Diastereo- and Enantioselective Michael Addition and 1,3-Dipolar Cycloaddition Reactions of Imino Esters to 3-Methyl-4-nitro-5-styrylisoxazoles

“…The model reaction of this simple styrylisoxazole with p -chloro-substituted substrate 2e was carried out using 5 mol % AgOAc/ThioClickFerrophos (TCF) catalyst and 18 mol % triethylamine in diethyl ether at −40 °C for 23 h. The conjugate addition reaction proceeded to give Michael adduct 3ae as the exclusive single diastereomer in a good yield with high ee %. Thus, 1a was revealed to be as good a Michael acceptor as nitroalkenes and α-enones . It must be noted that the cycloadduct was scarcely observed in the crude mixture.…”

“…In recent years, we and other research groups have demonstrated that 1-pyrroline-5-carboxylates are attractive cyclic azomethine ylides and could serve as building blocks of pyrroline and pyrrolidine frameworks . In this paper, we report asymmetric 1,6-conjugate addition of 3-methyl-4-nitro-5-styrylisoxazoles with 1-pyrroline-5-carboxylates catalyzed by the AgOAc/ThioClickFerrophos (a chiral P , S -ligand) complex (Scheme ).…”

Enantioselective Silver-Catalyzed Transformations

“…Besides chiral phosphine ligands, in 2005 Jørgensen et al introduced the use of cinchona alkaloids, such as hydrocinchonine, which were used in the presence of AgF in the 1,3-dipolar cycloaddition of azomethine ylides with acrylates to give the corresponding chiral cycloadducts in moderate enantioselectivities of up to 73% ee . In the period 2008–2014, different groups including those of Wang; − Najera, Sansano, and Cossio; − Kobayashi; − Fukuzawa; − Martin; − Hu; , Carretero and Adrio; , Zhao; Gong; and Deng; among others, ,− developed various other chiral silver catalysts based on bidentate ligands, such as biphosphines, aminophosphines, sulfur-containing phosphines, bisoxazolines, and diimines, but also monodentate ligands such as phosphoramidites, which were successfully applied to asymmetric 1,3-dipolar cycloadditions of azomethine ylides with a variety of activated olefins including malonates, maleimides, acrylates, nitroalkenes, and more complicated alkenes bearing electron-deficient groups. Since this period 2008–2014 has been recently covered by several reviews, − it will not be detailed in this section, which will only focus on the period 2015–2016.…”