New advances in asymmetric organocatalysis

• Radovan Šebesta

Beilstein J. Org. Chem. 2022, 18, 240–242, doi:10.3762/bjoc.18.28

• Radovan Sebesta Department of Organic Chemistry, Faculty of Natural Sciences, Comenius University in Bratislava, Mlynská dolina, Ilkovičova 6, 842 15 Bratislava, Slovakia 10.3762/bjoc.18.28 Keywords: asymmetric organocatalysis; covalent activation; noncovalent activation; Asymmetric catalysis is

• repertoire of chemical transformations that are amenable to organocatalysis [14]. Within the realm of covalent activation, chiral carbenes and phosphines are diverse and structurally rich groups of catalysts. The synthetic scope was greatly expanded by noncovalent activation via a range of proton-mediated

Copper-catalysed alkylation of heterocyclic acceptors with organometallic reagents

• Yafei Guo and
• Syuzanna R. Harutyunyan

Beilstein J. Org. Chem. 2020, 16, 1006–1021, doi:10.3762/bjoc.16.90

• research. In an attempt to overcome this reactivity issue, the same authors decided to use the trimethylsilyl-based Lewis acid TMSOTf in order to allow the covalent activation of the alkenylpyridine via pyridinium formation. This strategy turned out successful, and optimisation studies identified reaction

Chiral phase-transfer catalysis in the asymmetric α-heterofunctionalization of prochiral nucleophiles

• Johannes Schörgenhumer,
• Maximilian Tiffner and
• Mario Waser

Beilstein J. Org. Chem. 2017, 13, 1753–1769, doi:10.3762/bjoc.13.170

• highly enantioselective approaches have been reported so far, which clearly proves the potential of this non-covalent activation principle. Besides versatile stereoselective C–C bond-forming reactions, the asymmetric α-heterofunctionalization of prochiral nucleophiles (i.e., enolates) became one of the

Organocatalytic tandem Michael addition reactions: A powerful access to the enantioselective synthesis of functionalized chromenes, thiochromenes and 1,2-dihydroquinolines

• Chittaranjan Bhanja,
• Satyaban Jena,
• Sabita Nayak and
• Seetaram Mohapatra

Beilstein J. Org. Chem. 2012, 8, 1668–1694, doi:10.3762/bjoc.8.191

• through stereoselective covalent activation and hydrogen-bond interaction allowed this transformation to take place under mild reaction conditions (propanol as solvent at room temperature) and afforded dihydronitroquinoline derivatives 61 with moderate yields and moderate to good enantioselectivities