Recent developments in enantioselective photocatalysis

• Callum Prentice,
• James Morrisson,
• Andrew D. Smith and
• Eli Zysman-Colman

Beilstein J. Org. Chem. 2020, 16, 2363–2441, doi:10.3762/bjoc.16.197

• 222 (Scheme 34) [95]. A reductive quenching cycle is proposed using tetrahydroquinoxaline 223 as a sacrificial reductant to generate DPZ•−, which then reduces the organocatalyst-bound substrate 224 to give α-carbonyl radical 224•. Further reduction to the corresponding enolate and enantioselective

• protonation furnished the desired enantioenriched α-fluoroketones 225 in excellent yields and enantioselectivities (33 examples, up to >99:1 er). Jiang et al. used a related system for the enantioselective reduction of 1,2-diketones 227 (Scheme 35a) [96]. In this case the catalyst 228 is proposed to form

A review of asymmetric synthetic organic electrochemistry and electrocatalysis: concepts, applications, recent developments and future directions

• Munmun Ghosh,
• Valmik S. Shinde and
• Magnus Rueping

Beilstein J. Org. Chem. 2019, 15, 2710–2746, doi:10.3762/bjoc.15.264

• forms chiral ion pair B. The intermediate then undergoes enantioselective protonation by Yoh-H+ to generate Yoh-bound 9' (complex C). Subsequent release of the reduced product 9' and reprotonation of yohimbine complete the cycle (Scheme 9) [32][33]. In a continuation of their previous work [34], Wang

Conjugate addition–enantioselective protonation reactions

• James P. Phelan and
• Jonathan A. Ellman

Beilstein J. Org. Chem. 2016, 12, 1203–1228, doi:10.3762/bjoc.12.116

• assembly of more complex structures from simple precursors. In this review the addition of diverse protic and organometallic nucleophiles to electron-deficient alkenes followed by enantioselective protonation is summarized. Reactions are first categorized by the type of electron-deficient alkene and then

• are further classified according to whether catalysis is achieved with chiral Lewis acids, organocatalysts, or transition metals. Keywords: asymmetric catalysis; conjugate addition; enantioselective protonation; enolate; Introduction Due to their ubiquity in natural products and drugs, many

• researchers have developed methods for the stereoselective synthesis of tertiary carbon stereocenters. One aesthetically pleasing approach is the enantioselective protonation of prochiral enolates and enolate equivalents [1][2][3][4][5][6][7][8][9][10]. While an attractive strategy, the enantioselective

Application of the diastereoselective photodeconjugation of α,β-unsaturated esters to the synthesis of gymnastatin H

• Ludovic Raffier and
• Olivier Piva

Beilstein J. Org. Chem. 2011, 7, 151–155, doi:10.3762/bjoc.7.21

• observed for an enantioselective protonation transformation reaction. However, as the selectivities were highly dependent on the substrate, an alternative diastereoselective version has been developed. By using cheap and commercially available diacetone D-glucose (DAG-OH) as chiral alkoxy group and