Asymmetric Epoxidation of 1,1-Disubstituted Terminal Olefins by Chiral Dioxirane via a Planar-like Transition State

Abstract

Various 1,1-disubstituted terminal olefins have been investigated for asymmetric epoxidation using chiral ketone catalysts. Up to 88% ee has been achieved with a lactam ketone, and a planar transition state is likely to be a major reaction pathway.

Biologically inspired non-heme iron-catalysts for asymmetric epoxidation; design principles and perspectives

“…43 In parallel, their use as aliphatic alkene epoxidation catalysts useful in preparative scale was described by Jacobsen and co-workers. [53][54][55][56][57] After testing several amino acid derivatives, and N-protecting groups, the best result in terms of yield and enantioselectively was obtained using N-NPha-Ileu-OH (Figure 3). of H 2 O 2 and acetic acid as a key additive to ensure high product yields (Scheme 5).…”

Asymmetric Hydroboration of 1,1‐Disubstituted Alkenes

“…The Jacobsen-Katsuki [6] and Shi [7] epoxidations gave higher enantioselectivities, which are now approaching practical levels ( Table 2, entries 3 and 4). Until recently, only asymmetric hydrogenation and dihydroxylation reactions had provided more than 90 % ee ( Table 2, entries 5 and 6).…”

Green Organocatalytic Oxidative Methods using Activated Ketones

“…Numerous efforts have been made to improve this catalytic system, and perhaps the most widely employed protocol is that developed by Shi and co‐workers in 1996. The Shi oxidation allows the epoxidation of various alkenes by utilizing easy‐to‐prepare fructose derivative 9 as the organocatalyst and Oxone (KHSO 5 ) as the oxidant (Scheme ) …”