The combined use of rhodium and cinchona-based squaramide has first been introduced for asymmetric relay catalysis, enabling a highly enantioselective semipinacol rearrangement/Michael addition cascade.
Reactivity Profiles of Diazo Amides, Esters, and Ketones in Transition-Metal-Free C–H Insertion Reactions
作者:Sarah E. Cleary、Xin Li、Li-Cheng Yang、K. N. Houk、Xin Hong、Matthias Brewer
DOI:10.1021/jacs.8b12420
日期:2019.2.27
Vinyl cations derived from diazo ketones participate in transition-metal-free C-H insertion reactions, but the corresponding amide and ester analog exhibit divergent reactivity profiles. Whereas cations formed from diazo ketones undergo a rearrangement and C-H insertion sequence, those from diazo amides do so less efficiently and tend to be competitively trapped before the insertion step occurs. Diazo