Enantio- and Regioselective Dihydroboration of Enals

ACS Catalysis, Journal Year: 2024, Volume and Issue: 14(6), P. 3977 - 3985

Published: Feb. 28, 2024

Asymmetric hydroboration is among the most powerful and straightforward methods to construct chiral organoboron compounds, which are extensively used in natural products, bioactive molecules, materials science. Among them, enantioselective of a single functional group has been well-established experienced significant advances, but asymmetric multiple groups rarely developed due extremely challenging chemo-, regio-, enantioselectivity control. Herein, we present Co-catalyzed enantio- regioselective dihydroboration enals achieved both C═O bond C═C bond. This protocol features mild reaction conditions, wide substrate scope, good tolerance provides highly efficient method for preparation valuable 1,4-borylethers their downstream products such as 1,4-diols amino alcohols. Preliminary mechanistic studies suggested that this involved tandem 1,2-hydroboration/dissociative isomerization/asymmetric process.

Language: Английский

Ligand-Controlled Cobalt-Catalyzed Regiodivergent and Stereoselective Ring-Opening Isomerization of Vinyl Cyclopropanes

Organic Letters, Journal Year: 2024, Volume and Issue: 26(23), P. 5004 - 5009

Published: June 3, 2024

A ligand-controlled regiodivergent and stereoselective ring-opening isomerization of vinylcyclopropane was developed with cobalt catalysis. Employing the commercially available Xantphos ligand, reactions afforded exclusively linear-type 1,3-dienes as products. Interestingly, when switching ligand to an amido-diphosphine (PNP), branched-type were obtained high regioselectivity stereoselectivity. Preliminary mechanistic investigations suggested that a π-allyl metal metal-hydride species are involved key intermediates in two transformations, respectively.

Language: Английский