Regio- and Enantioselective Rhodium-Catalyzed Allylic Alkylation of Racemic Allylic Alcohols with 1,3-Diketones

Abstract

Highly regio- and enantioselective rhodium-catalyzed allylic alkylation of 1,3-diketones with racemic secondary allylic alcohols is reported. In the presence of a Rh-catalyst derived from the Carreira (P, olefin)-ligand and TFA as an additive, chiral branched α-allylated 1,3-diketones could be obtained in good to excellent yields, with excellent regio- and enantioselectivity ( b/ l > 19/1, 86-98% ee). The direct utilization of allyl alcohols as electrophiles represents an improvement from the viewpoint of an atom economy. Both aryl- and aliphatic-substituted allyl alcohols are suitable substrates with excellent reaction outcomes. This reaction features mild conditions, broad substrate scope, and readily available substrates.

Highly atroposelective synthesis of nonbiaryl naphthalene-1,2-diamine N-C atropisomers through direct enantioselective C-H amination

“…5c. Allylic alkylation is an important component of chemistry and enantioselective studies, and particularly those of allylic alcohols, rely heavily on transition metals 57–59 . The para -position of the aniline C-H allylic alkylation was not reported.…”

Rhodium-Catalyzed Allylation Reactions

“…The mechanism goes through direct addition of a nucleophile to the metal center followed by reductive elimination (innersphere mechanism). The stereochemical course of this reaction was established through the synthesis of (S)-ibuprofen (30).…”

Ligand-Dependent Regiodivergent Enantioselective Allylic Alkylations of α-Trifluoromethylated Ketones

“…The reverse of the absolute con guration was obtained with L6 (entry 6). When switching to mono-dentate binaphthol-derived phosphoramidite L7, 37,38 increased ratio of the C1 adduct 3a was observed (entry 7, 35:65). SIPHOS L8 resulted in a good regioselectivity (85:15) and 97% ee (entry 8).…”