13720-37-1Relevant articles and documents
Bifunctional copper catalysts, a one step synthesis of bicyclic ethers starting from α,β-unsaturated ketones
Ravasio, Nicoletta,Leo, Vincenzo,Babudri, Francesco,Gargano, Michele
, p. 7103 - 7106 (1997)
A new, one pot synthesis of bicyclic ethers starting from α,β-unsaturated ketones containing an additional isolated olefinic bond is proposed. It relies on highly chemoselective hydrogenation of the enone group to the corresponding alcohol in the presence of supported copper catalysts, and on the presence of acidic sites on the catalyst support activating the double bond as a carbocation.
Reduction of α,β-Unsaturated Carbonyl Compounds to the Saturated Alcohols Using Hydridocarbonyliron Complexes
Yamashita, Masakazu,Miyoshi, Kanako,Okada, Yasuhiro,Suemitsu, Rikisaku
, p. 1329 - 1330 (1982)
Tetracarbonylhydridoferrate was found to be effective for the selective reduction of α,β-unsaturated carbonyl compounds to the corresponding saturated alcohols.The reactions proceeded stereospecifically and (-)- and (+)-neodihydrocarveol were obtained exclusively from (+)- and (-)-carvone respectively.The reaction mechanism is briefly discussed.
BIOTRANSFORMATION OF α- AND β-IONONES BY IMMOBILIZED CELLS OF NICOTIANA TABACUM
Tang, Yi-Xiong,Suga, Takayuki
, p. 737 - 740 (1994)
Immobilized cells of Nicotiana tabacum reduced the carbon-carbon double bond adjacent to the carbonyl group and then the carbonyl group itself of the dienone compounds, α-ionone and β-ionone: In addition, the selectivity for the reduction of the double bond adjacent to the carbonyl group could be enhanced by performing the biotransformation in medium with a pH near the optimal pH of the enone reductase which specifically catalyses the reduction of the α,β-unsaturated double bond of s-trans-enones. - Key words: Nicotiana tabacum; Solanaceae; plant cell cultures; immobilized cells; dienone; β-ionone; α-ionone; biotransformation.
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
supporting information, 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.
Capturing the Monomeric (L)CuH in NHC-Capped Cyclodextrin: Cavity-Controlled Chemoselective Hydrosilylation of α,β-Unsaturated Ketones
Bistri-Aslanoff, Olivia,Derat, Etienne,Leloux, Sébastien,Leyssens, Tom,Ménand, Micka?l,Meijide Suárez, Jorge,Riant, Olivier,Roland, Sylvain,Sollogoub, Matthieu,Xu, Guangcan,Zhang, Pinglu,Zhang, Yongmin
, p. 7591 - 7597 (2020/03/23)
The encapsulation of copper inside a cyclodextrin capped with an N-heterocyclic carbene (ICyD) allowed both to catch the elusive monomeric (L)CuH and a cavity-controlled chemoselective copper-catalyzed hydrosilylation of α,β-unsaturated ketones. Remarkably, (α-ICyD)CuCl promoted the 1,2-addition exclusively, while (β-ICyD)CuCl produced the fully reduced product. The chemoselectivity is controlled by the size of the cavity and weak interactions between the substrate and internal C?H bonds of the cyclodextrin.
Diethylsilane as a Powerful Reagent in Au Nanoparticle-Catalyzed Reductive Transformations
Louka, Anastasia,Kidonakis, Marios,Saridakis, Iakovos,Zantioti-Chatzouda, Elisavet-Maria,Stratakis, Manolis
, p. 3508 - 3514 (2020/06/02)
Diethylsilane (Et2SiH2), a simple and readily available dihydrosilane, that exhibits superior reactivity, as compared to monohydrosilanes, in a series of reductive transformations catalyzed by recyclable and reusable Au nanoparticles (1 mol-%) supported on TiO2. It reduces aldehydes or ketones almost instantaneously at ambient conditions. It can be used in a one pot rapid reductive amination procedure, in which premixing of aldehyde and amine is required prior to the addition of the reducing agent and the catalyst, even in a protic solvent. An unprecedented method for the synthesis of N-arylisoindolines is also shown in the reductive amination between o-phthalaldehyde and anilines. In this transformation, it is proposed that the intermediate N,2-diphenylisoindolin-1-imines are reduced stepwise to the isoindolines. Finally, Et2SiH2 readily reduces amides into amines in excellent yields and shorter reaction times relative to previously known analogous nano Au(0)-catalyzed protocols.
Selective reduction of dienes/polyenes using sodium borohydride/catalytic ruthenium(III) in various liquid amide aqueous mixtures
Babler, James H.,Ziemke, David W.,Hamer, Robert M.
, p. 1754 - 1757 (2013/04/10)
An efficient method to effect selective reduction of several structurally diverse dienes and an unsymmetrical triene is reported. The reduction is facile at 0 °C in a liquid amide aqueous solution containing sodium borohydride in the presence of 15 mol % ruthenium(III) chloride. The chemoselectivity of the reaction is controlled by proper choice of the liquid amide solvent.
Chlorosulfonic acid as a convenient electrophilic olefin cyclization agent
Linares-Palomino, Pablo J.,Salido, Sofía,Altarejos, Joaquín,Sánchez, Adolfo
, p. 6651 - 6655 (2007/10/03)
Among several sulfonic acids studied (MeSO3H, p-TsOH, H2SO4, ClSO3H, FSO3H), the scarcely used chlorosulfonic acid showed to be an efficient agent for electrophilic olefin cyclizations with internal nucleophilic termination, in a similar manner that is well-established with fluorosulfonic acid. Its availability, lower price and relatively lesser handling problems makes ClSO3H an advantageous cyclizing agent particularly for high-scale applications. The stereochemical outcome of these cyclizations has been rationalized.
A Synthetic Study of (-)-Dihydroedulan II and Related Compounds
Sugai, Takeshi,Yokoshi, Tomoki,Watanabe, Naoyuki,Ohta, Hiromichi
, p. 7227 - 7236 (2007/10/02)
(-)-Dihydroedulan II and related compounds were synthesized from (2R,1'RS)-dihydro-α-ionol, which was prepared by lipase-catalyzed enantioselective transesterification of the corresponding diastereomeric mixture as the key-step.Fungal allylic oxidation of (-)-dihydroedulan II worked well to afford a corresponding alcohol as well as (+)-dihydroedulan-8-one.
A NOVEL SELENIUM-MEDIATED SPIROANNELATION: ONE-STEP PREPARATION OF d1-THEASPIRANE FROM α-DIHYDROIONOL
Uneyama, Kenji,Fujibayashi, Shoji,Torii, Sigeru
, p. 4637 - 4638 (2007/10/02)
dl-Theaspirane (1) was prepared by the selenium-mediated electrochemical oxidation of α-dihydroionol (2), via a novel selenium-mediated spiroannelation.
