253684-23-0Relevant articles and documents
A Radical-Initiated Fragmentary Rearrangement Cascade of Ene-Ynamides to [1,2]-Annulated Indoles via Site-Selective Cyclization
Li, Sifan,Wang, Yu,Wu, Zibo,Shi, Weiliang,Lei, Yibo,Davies, Paul W.,Shu, Wei
, p. 7209 - 7214 (2021/09/14)
Straightforward access to [1,2]-annulated indoles, key substructures in natural products, is highly desirable yet challenging. Herein, a radical triggered fragmentary cyclization cascade reaction of ene-ynamides is presented, providing a rapid access into [1,2]-annulated indoles by an intermolecular radical addition, intramolecular cyclization, desulfonylative aryl migration, and site-selective C(sp2)-N cyclization sequence. DFT calculations support oxidation of N-centered radical species to cations prior to the C-N bond formation, followed by an unusual aza-Nazarov cyclization.
Cs2CO3-Mediated Vicinal Thiosulfonylation of 1,1-Dibromo-1-Alkenes with Thiosulfonates: An Expedient Synthesis of (E)-1,2-Thiosulfonylethenes
Reddy, Raju Jannapu,Kumari, Arram Haritha,Kumar, Jangam Jagadesh,Nanubolu, Jagadeesh Babu
supporting information, p. 1587 - 1591 (2019/02/16)
A new and highly efficient vicinal thiosulfonylation of 1,1-dibromo-1-alkenes with thiosulfonates in the presence of cesium carbonate has been developed. The metal-free diheterofunctionalization is an operationally simple to access a wide range of (E)-1,2-thiosulfonylethenes (α-aryl-β-thioarylvinyl sulfones) in moderate to high yields with high levels of stereoselectivities. Further, scalable reactions have been demonstrated for this transformation, thus illustrating its efficiency and practicality. (Figure presented.).
Catalytic Enantioselective Synthesis of 1,4-Keto-Alkenylboronate Esters and 1,4-Dicarbonyls
Liang, Michael Z.,Meek, Simon J.
supporting information, p. 14234 - 14239 (2019/08/30)
A catalytic enantioselective method for the synthesis of 1,4-keto-alkenylboronate esters by a rhodium-catalyzed conjugate addition pathway is disclosed. A variety of novel, bench-stable alkenyl gem-diboronate esters are synthesized. These easily accessible reagents react smoothly with a collection of cyclic α,β-unsaturated ketones, generating a new C?C bond and stereocenter. Products are isolated in up to 99 % yield with greater than 20:1 E/Z and greater than 99:1 e.r. Mechanistic studies show the site-selectivity of transmetalation and reactivity is ligand dependent. The utility of the approach is highlighted by gram-scale synthesis of enantioenriched cyclic 1,4-diketones, and stereoselective transformations of the products by hydrogenation, allylation, and isomerization.
