1450891-89-0Relevant articles and documents
Enantiospecific Solvolytic Functionalization of Bromochlorides
Burckle, Alexander J.,Gál, Bálint,Seidl, Frederick J.,Vasilev, Vasil H.,Burns, Noah Z.
supporting information, p. 13562 - 13569 (2017/10/05)
Herein, we report that under mild solvolytic conditions, enantioenriched bromochlorides can be ionized, stereospecifically cyclized to an array of complex bromocyclic scaffolds, or intermolecularly trapped by exogenous nucleophiles. Mechanistic investigations support an ionic mechanism wherein the bromochloride serves as an enantioenriched bromonium surrogate. Several natural product-relevant motifs are accessed in enantioenriched form for the first time with high levels of stereocontrol, and this technology is applied to the scalable synthesis of a polycyclic brominated natural product. Arrays of nucleophiles including olefins, alkynes, heterocycles, and epoxides are competent traps in the bromonium-induced cyclizations, leading to the formation of enantioenriched mono-, bi-, and tricyclic products. This strategy is further amenable to intermolecular coupling between cinnamyl bromochlorides and a diverse set of commercially available nucleophiles. Collectively, this work demonstrates that enantioenriched bromonium chlorides are configurationally stable under solvolytic conditions in the presence of a variety of functional groups.
Catalytic enantioselective dibromination of allylic alcohols
Hu, Dennis X.,Shibuya, Grant M.,Burns, Noah Z.
supporting information, p. 12960 - 12963 (2013/09/24)
A new dibromination reaction involving the combination of dibromomalonate as the bromonium source and a titanium bromide species as the bromide source has been developed. Enantioselective catalysis has been achieved through apparent ligand acceleration by a tartaric acid-derived diol.
