54322-84-8Relevant academic research and scientific papers
FeCl3·6H2O-catalyzed mukaiyama-aldol type reactions of enolizable aldehydes and acetals
Rodríguez-Gimeno, Alejandra,Cuenca, Ana B.,Gil-Tomás, Jesús,Medio-Simón, Mercedes,Olmos, Andrea,Asensio, Gregorio
, p. 8263 - 8270 (2015/03/18)
Mukaiyama-aldol type reactions of acetals derived from enolizable aldehydes with FeCl3·6H2O, an eco-friendly, low-cost, and stable catalyst, lead to β-methoxycarbonyl compounds with nearly quantitative yields. The methodology is extended to the parent aldehydes as starting materials, leading to the corresponding aldols with lower yields, but efficiently. Different alkyl and aryl substituted acetals and aldehydes have been tested in the reaction with linear and cyclic silyl enol ethers. Reactions are carried out in an open air atmosphere, and additives are not required. Acetals can be considered activating groups of the carbonyl moiety rather than a protecting group in this type of FeCl3·6H2O-catalyzed condensation.
Sulfur-directed olefin oxidations: Observation of divergent reaction mechanisms in the palladium-mediated acetoxylation of unsaturated thioacetals
Mann, Sam E.,Aliev, Abil E.,Tizzard, Graham J.,Sheppard, Tom D.
scheme or table, p. 1772 - 1775 (2011/06/22)
The Pd-mediated oxidation of unsaturated thioacetals gives either allyl or vinyl esters, depending on the substrate structure. We report the characterization of a range of sulfur-stabilized palladium intermediates via a combined computational and experime
NOVEL BETA-HYDROXYKETONES AND BETA-ALKOXYKETONES WITH ESTROGENIC ACTIVITY
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Page/Page column 33-34, (2009/06/27)
This invention relates to β-hydroxyketones and β-alkoxyketones of formula (I), to their use as estrogen receptor modulators, and to methods for their preparation.
Intramolecular O-H...O hydrogen-bond-mediated reversal in the partitioning of conformationally restricted triplet 1,4-biradicals and amplification of diastereodifferentiation in their lifetimes
Moorthy, Jarugu Narasimha,Samanta, Subhas,Koner, Apurba L.,Saha, Satyajit,Nau, Werner M.
supporting information; experimental part, p. 13608 - 13617 (2009/02/06)
The photoreactivity and nanosecond transient phenomena have been investigated for a rationally designed set of ketones 4-9 in order to gain comprehensive insights concerning the influence of intramolecular hydrogen bonding on (i) the lifetimes of triplet 1,4-biradicals and (ii) the partitioning of the latter between cyclization and elimination. Comparisons of the photochemical results and lifetime data for the biradicals of ketones 6 versus 8 and 7 versus 9 revealed a remarkable influence of hydrogen bonding when superimposed upon steric factors: while 6 and 7 yielded cyclobutanols in poor yields, cyclization was found to be overwhelmingly predominant for 8-anti and moderately so for 9-anti, with a high stereoselectivity in the formation of cyclobutanols (>95% for 8-anti). The diastereochemistry in the case of 8 permitted the occurrence of fragmentation or cyclization almost exclusively (>90% cyclization for 8-anti and >75% elimination for 8-syn). Significantly, the intramolecular hydrogen bonding in the biradicals of 8 and 9 was found to reverse their partitioning between cyclization and elimination compared with the behavior of the biradicals of ketones 3; the ketones 8-anti and 9-anti underwent cyclization in benzene, predominantly leading to cyclobutanols with syn stereochemistry between the C2 and C3 substituents. In accordance with photoproduct profiles, an unprecedented ~2-fold difference in the lifetimes of the intermediate diastereomeric triplet biradicals of ketones 8 in nonpolar solvents (e.g., τsyn = 123 ns and τanti = 235 ns in cyclohexane) was observed via nanosecond laser flash photolysis, while no such difference in lifetimes was found for the triplet biradicals of acetoxy ketones 9. The intriguing diastereodifferentiation in the lifetimes of the diastereomeric triplet 1,4-biradicals of 8 and the product profiles of ketones 6, 7, and 9 are best reconciled via a unified mechanistic picture in which superposition of steric factors over varying magnitudes of O-H...O hydrogen bonding selectively facilitates a particular pathway. In particular, the diastereodifferentiation in the photochemical outcomes for the diastereomers of ketone 8 and in the lifetimes of their triplet biradicals can be understood on the basis of rapid deactivation of the 8-syn triplet biradical via fragmentation and slow cyclization of the 8-anti triplet biradical from chair- and twist-boat-like hydrogen-bonded conformations, respectively. The photolysis in polar aprotic solvents such as DMSO and pyridine was found to reverse the chemoselectivity, yielding reactivity paralleling that of ketones 3, for which the steric factors between the C2 and C3 substituents control the photochemical outcome.
Synthesis and evaluation of estrogen agonism of diaryl 4,5- dihydroisoxazoles, 3-hydroxyketones, 3-methoxyketones, and 1,3-diketones: A compound set forming a 4D molecular library
Pulkkinen, Juha T.,Honkakoski, Paavo,Per?kyl?, Mikael,Berczi, Istvan,Laatikainen, Reino
supporting information; experimental part, p. 3562 - 3571 (2009/04/06)
In this paper, the preparation and systematic evaluation of estrogen receptor α (ERα) and estrogen receptor β (ERβ) activities of some diaryl-1,3-diones and their synthetic intermediates, diaryl-4,5-dihydroisoxazoles, diaryl-3-hydroxyketones, diaryl-3-met
Neodymium(III)-mediated reformatsky-type reactions of α-halo ketones with carbonyl compounds
Kirsch, Stefan F.,Liebert, Clemence
, p. 3711 - 3717 (2008/03/18)
In a neodymium(III) iodide induced process, α-bromo ketones 1 and aldehydes 2 are effectively converted into aldol products 3. This Reformatsky-type reaction proceeds through the formation of a neodymium enolate at room temperature in CH2Cl2. The analogous reaction in the presence of NdBr3/NaI at 50°C in THF favors the formation of corresponding aldol-Tishchenko products 5 in good yields. Studies to define the scope and limitations of these reactions mediated by neodymium(III) salts are also described. Wiley-VCH Verlag GmbH & Co. KGaA, 2007.
One-pot reduction-aldol reaction of esters
Sasaki, Mikio,Yudin, Andrei K.
, p. 2443 - 2444 (2007/10/03)
We have developed a new protocol for making aldol adducts in a one-pot reaction between esters and silyl enol ethers in the presence of DIBALH without isolating the intermediate aldehydes. Lewis acid activation of the initially formed aluminated hemiacetals produces highly reactive electrophilic aldehyde equivalents in situ. Using this protocol, various aldol adducts can be readily obtained in up to 90% yield on a large scale.
Further Investigations into the Mechanism of the Acid Catalysed Rearrangement of Aryl Substituted Cyclopropyl Ketones
Hantawong, Kesra,Murphy, William S.
, p. 2520 - 2547 (2007/10/02)
The acid catalysed rearrangement of a number of aryl cyclopropyl ketones (2) to tetralones (3) were investigated in situ by 1H and 13C n.m.r. spectroscopy.The formation of oxycyclopentenyl intermediates (4) were observed.The involvement of a concurrent el
