SOMOphilic alkyne vs radical-polar crossover approaches: The full story of the azido-alkynylation of alkenes

• Julien Borrel and
• Jerome Waser

Beilstein J. Org. Chem. 2024, 20, 701–713, doi:10.3762/bjoc.20.64

• high yield (72%) of the homopropargylic azide was reached. Full insights are given about the factors that were essential for the success of the optimization process. Keywords: alkyne; azide; hypervalent iodine; photoredox; trifluoroborate salt; Introduction Homopropargylic azides are important

Enolates ambushed – asymmetric tandem conjugate addition and subsequent enolate trapping with conventional and less traditional electrophiles

• Péter Kisszékelyi and
• Radovan Šebesta

Beilstein J. Org. Chem. 2023, 19, 593–634, doi:10.3762/bjoc.19.44

• , transformation to potassium trifluoroborate salt, hydrolysis, C–C cross-coupling, base-mediated elimination, radical C–B cleavage) [72]. Therefore, enantioenriched boronates are commonly applied intermediates in organometallic, medicinal, and other fields of chemistry. At the same time, some organoboronic acid

• stereoselective conjugate borylation of cyclobutene 1-carboxyester 175 (Scheme 45A) [87]. As a result, the cis-β-boronyl cyclobutylcarboxyester 176 was prepared on a gram scale with 80% yield and an excellent 99% ee (dr >20:1). Subsequent transformation to the corresponding trifluoroborate salt 177 resulted in a

Photocatalysis with organic dyes: facile access to reactive intermediates for synthesis

• Stephanie G. E. Amos,
• Marion Garreau,
• Luca Buzzetti and
• Jerome Waser

Beilstein J. Org. Chem. 2020, 16, 1163–1187, doi:10.3762/bjoc.16.103

• radical adds to the imine substrate 5.5, yielding the desired amine product 5.6. Finally, the same group developed a photochemical radical alkylation of heteroarenes with alkyl trifluoroborate salts (Scheme 6) [51]. In this reaction, the photoinduced oxidative fragmentation of the alkyl trifluoroborate

• salt 6.1 was promoted by the acridinium photocatalyst OD2. The resulting alkyl radical can be intercepted by a protonated heteroarene 6.2. The addition of potassium persulfate leads to the regeneration of the photocatalyst and the rearomatization of the intermediate, delivering the desired alkylated