17283-81-7Relevant articles and documents
Conversion of α,β-unsaturated ketones into α-hydroxy ketones using an Mn(III) catalyst, phenylsilane and dioxygen: Acceleration of conjugate hydride reduction by dioxygen
Magnus,Payne,Waring,Scott,Lynch
, p. 9725 - 9730 (2000)
Treatment of a variety of α,β-unsaturated ketones with Mn(dpm)3 (3 mol%)/PhSiH3 (1.3 equiv.)/isopropyl alcohol/O2, followed by reductive work-up with P(OEt)3 resulted in the formation of α-hydroxy-ketones. (C) 2000 Elsevier Science Ltd.
Bioluminescence in the limpet-like snail, latia neritoides
Ohmiya, Yoshihiro,Kojima, Satoshi,Nakamura, Mitsuhiro,Niwa, Haruki
, p. 1197 - 1205 (2005)
Latia neritoides is a small limpet-like snail that produces a bright green bioluminescence; it is found only in New Zealand streams. The light-emitting system is unique. Although Latia bioluminescence has been studied since 1880, its mechanism is unclear. Shimomura and Johnson clarified the elements of the mechanism, including the structures of luciferin and luciferase, in 1968. However, neither the emitter nor the mechanism of the excited state of luciferin has been determined. We studied molecular mechanisms to clarify the characteristics of luciferin and luciferase and to produce a new application for this system.
Shimomura,Johnson
, p. 2574,2579 (1968)
Asymmetric Cation-Olefin Monocyclization by Engineered Squalene–Hopene Cyclases
Aeberli, Natalie,Berweger, Raphael,Bornscheuer, Uwe T.,Buller, Rebecca,Dossenbach, Sandro,Eichenberger, Michael,Eichhorn, Eric,Flachsmann, Felix,Hüppi, Sean,Hortencio, Lucas,Patsch, David,Voirol, Francis,Vollenweider, Sabine
, p. 26080 - 26086 (2021/09/20)
Squalene–hopene cyclases (SHCs) have great potential for the industrial synthesis of enantiopure cyclic terpenoids. A limitation of SHC catalysis has been the enzymes’ strict (S)-enantioselectivity at the stereocenter formed after the first cyclization step. To gain enantio-complementary access to valuable monocyclic terpenoids, an SHC-wild-type library including 18 novel homologs was set up. A previously not described SHC (AciSHC) was found to synthesize small amounts of monocyclic (R)-γ-dihydroionone from (E/Z)-geranylacetone. Using enzyme and process optimization, the conversion to the desired product was increased to 79 %. Notably, analyzed AciSHC variants could finely differentiate between the geometric geranylacetone isomers: While the (Z)-isomer yielded the desired monocyclic (R)-γ-dihydroionone (>99 % ee), the (E)-isomer was converted to the (S,S)-bicyclic ether (>95 % ee). Applying the knowledge gained from the observed stereodivergent and enantioselective transformations to an additional SHC-substrate pair, access to the complementary (S)-γ-dihydroionone (>99.9 % ee) could be obtained.
Photocontrolled Cobalt Catalysis for Selective Hydroboration of α,β-Unsaturated Ketones
Beltran, Frédéric,Bergamaschi, Enrico,Funes-Ardoiz, Ignacio,Teskey, Christopher J.
supporting information, p. 21176 - 21182 (2020/09/17)
Selectivity between 1,2 and 1,4 addition of a nucleophile to an α,β-unsaturated carbonyl compound has classically been modified by the addition of stoichiometric additives to the substrate or reagent to increase their “hard” or “soft” character. Here, we demonstrate a conceptually distinct approach that instead relies on controlling the coordination sphere of a catalyst with visible light. In this way, we bias the reaction down two divergent pathways, giving contrasting products in the catalytic hydroboration of α,β-unsaturated ketones. This includes direct access to previously elusive cyclic enolborates, via 1,4-selective hydroboration, providing a straightforward and stereoselective route to rare syn-aldol products in one-pot. DFT calculations and mechanistic experiments confirm two different mechanisms are operative, underpinning this unusual photocontrolled selectivity switch.
