Continuous-flow enantioselective α-aminoxylation of aldehydes catalyzed by a polystyrene-immobilized hydroxyproline

• Xacobe C. Cambeiro,
• Rafael Martín-Rapún,
• Pedro O. Miranda,
• Sonia Sayalero,
• Esther Alza,
• Patricia Llanes and
• Miquel A. Pericàs

Beilstein J. Org. Chem. 2011, 7, 1486–1493, doi:10.3762/bjoc.7.172

• preformed enolates, both with the use of chiral auxiliaries (chiral, enantiopure enolates and achiral oxidizing agents, or achiral enolates and chiral, enantiopure oxidizing agents) [3][4][5] and by Mukaiyama-type catalytic processes involving preformed achiral enolate equivalents and achiral oxidants, with

Alkene selenenylation: A comprehensive analysis of relative reactivities, stereochemistry and asymmetric induction, and their comparisons with sulfenylation

• Vadim A. Soloshonok and
• Donna J. Nelson

Beilstein J. Org. Chem. 2011, 7, 744–758, doi:10.3762/bjoc.7.85

• reactivity of organoselenium compounds, it is expected that chiral selenium containing derivatives could be synthetically useful as chiral auxiliaries or intermediates for the development of a novel asymmetric methodology platform [15][16][17][18]. Furthermore, compared with sulfur analogs [44], chiral

• considered generally more efficient chiral auxiliaries compared with compound 1 [27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43]. Reactions of benzeneselenenyl halides, including chiral compounds 1–3, with alkenes generally [55][56] exhibit high Markovnikov regioselectivity [57], with

Effects of anion complexation on the photoreactivity of bisureido- and bisthioureido-substituted dibenzobarrelene derivatives

• Heiko Ihmels and
• Jia Luo

Beilstein J. Org. Chem. 2011, 7, 278–289, doi:10.3762/bjoc.7.37

• asymmetric photoreactions have been conducted with remarkable enantioselectivity in homogeneous solution, whereas reports of asymmetric di-π-methane rearrangements in solutions are relatively rare. Chiral auxiliaries attached as ester or amide functionalities at the vinylic positions of dibenzobarrelene

Enantioselective synthesis of tricyclic amino acid derivatives based on a rigid 4-azatricyclo[5.2.1.0^2,6]decane skeleton

• Matthias Breuning,
• Tobias Häuser,
• Christian Mehler,
• Christian Däschlein,
• Carsten Strohmann,
• Andreas Oechsner and
• Holger Braunschweig

Beilstein J. Org. Chem. 2009, 5, No. 81, doi:10.3762/bjoc.5.81

• β-turn-inducing building blocks in peptidomimetics and for chiral auxiliaries in asymmetric organocatalysis. Keywords: amino acid; enantioselective synthesis; norbornane; polycyclic compounds; pyrrolidine; Introduction Unnatural amino acids with a rigid bowl-shaped backbone have received

• are promising candidates as ß-turn-inducing building blocks in peptidomimetics and as chiral auxiliaries in organocatalysis. The conformationally rigid amino acid derivatives 1–3 (β-turn-inducing building blocks) and 4–6 (successful organocatalysts). The targeted tricyclic amino acid derivatives 7 and

Conformational rigidity of silicon- stereogenic silanes in asymmetric catalysis: A comparative study

• Sebastian Rendler and
• Martin Oestreich

Beilstein J. Org. Chem. 2007, 3, No. 9, doi:10.1186/1860-5397-3-9

• based on silicon-stereogenic reagents or substrates were revisited or invented. [1][2][3][4] Aside from the use of silicon-stereogenic chiral auxiliaries in substrate-controlled reactions, [5] a still limited number of remarkable stereoselective processes with a stereogenic silicon as the reactive site