17553-86-5Relevant articles and documents
Grieco et al.
, p. 573 (1976)
β-Homoamino acids as catalysts in enantioselective intra- and intermolecular aldol reactions
Limbach, Michael
, p. 3843 - 3847 (2006)
β3-Homoamino acids catalyze the intra- (cf. the Hajos-Parrish-Eder-Sauer-Wiechert reaction) as well as the intermolecular aldol reaction. The stereochemical outcome with selectivities of up to 83% ee is reversed in the intramolecular reaction,
Protecting-group-free total synthesis of aplykurodinone-1
Tang, Yu,Liu, Ji-Tian,Chen, Ping,Lv, Ming-Can,Wang, Zhen-Zhen,Huang, Yi-Kun
, p. 11729 - 11734 (2014)
A concise, stereoselective, and protecting-group-free total synthesis of aplykurodinone-1 from Hajos-Parrish ketone was described. The synthetic approach features a sequence of aerobic allylic oxidation and elimination of alcohol 9. The key intermediate for this synthesis was formed by a stereoselective intramolecular radical cyclization.
Inotropic activity of hydroindene amidinohydrazones
Sevillano,Melero,Caballero,Tomé,Lelièvre,Geering,Crambert,Carrón,Medarde,San Feliciano
, p. 127 - 136 (2002)
Several hydroindenic derivatives (7a-methyl-2,3,5,6,7,7a-hexahydro-1H-indenes), bearing an amidinohydrazone at C-5 and different moieties at C-1, have been synthesized and evaluated for their inotropic and chronotropic effects on right- and left-guinea-pig-atria activity. Three of them showed the same profile as digoxin, although with lower potency. The effect on Na+,K+ ATPase (NKA) was also evaluated for these three compounds, observing that two of them, with the same absolute configuration as natural cardenolides, are also NKA inhibitors, while the compound with the opposite configuration lacks such an effect. More interestingly, both active compounds act without affecting the cardiac rhythm. This could be related to the selective inhibition of the human α2β1 isozyme (associated with the inotropic effect) with respect to the α1β1 isozyme (associated with the maintenance of basal ionic levels in the cell and the toxic effect of cardenolides).
Construction of key building blocks towards the synthesis of cortistatins
Indu, Satrajit,Kaliappan, Krishna P.,Telore, Rahul D.
supporting information, p. 2432 - 2446 (2020/04/22)
This work reports the construction of key building blocks towards the synthesis of cortistatins; a family of steroidal alkaloids. Cortistatin A, being a primary target due to its superior biological properties over other congeners, has been prepared by two different synthetic routes. Synthesis of the precursor to the heavily substituted A-ring starting from d-glucose and construction of the DE-ring junction employing a Hajos-Parrish ketone as a chiral pool have been demonstrated. Efforts are underway to assemble these key fragments and build towards the total synthesis of cortistatin A.
A Highly Active Polymer-Supported Catalyst for Asymmetric Robinson Annulations in Continuous Flow
Canellas, Santiago,Ayats, Carles,Henseler, Andrea H.,Pericàs, Miquel A.
, p. 1383 - 1391 (2017/08/09)
The preparation through Robinson annulation of enantiopure building blocks with both academic and industrial relevance, such as the Wieland-Miescher and Hajos-Parrish ketones, has suffered from important drawbacks, such as the need for high catalyst loading or extremely long reaction times. Here we report a heterogenized organocatalyst based on Luo's diamine for fast and broad-scope enantioselective Robinson annulation reactions. The polystyrene-supported diamine 19a enables the high-yield, highly enantioselective preparation of a wide range of chiral bicyclic enones under mild conditions, with reaction times as short as 60 min (batch) or residence times of 10 min (flow). In contrast with its homogeneous counterpart 19b, the catalytic resin 19a experiences a notable increase in catalytic activity with temperature in 2-MeTHF (a 10-fold decrease in reaction times without erosion in enantioselectivity is observed from room temperature to 55 °C). The scope of the transformation in batch mode has been illustrated with 14 examples, including examples only reported in poorly enantioenriched (22n) or in racemic form (22k). Enantiopure 22k has been used as the starting material for a straightforward formal synthesis of the antibiotic and antifeedant sesquiterpene (-)-isovelleral (24). The heterogenized catalyst 19a admits extended recycling (10 cycles) and has been used to develop the first asymmetric Robinson annulations in continuous flow. The potential of the flow process is illustrated by the large-scale preparation of the Wieland-Miescher ketone (65 mmol in 24 h of operation, TON of 117) and by a sequential flow experiment leading to a library of eight enantioenriched diketone compounds.
Bifunctional organocatalysts based on a carbazole scaffold for the synthesis of the Hajos-Wiechert and Wieland-Miescher ketones
Rubio, Omayra H.,Fuentes De Arriba, ángel L.,Monleón, Laura M.,Sanz, Francisca,Simón, Luis,Alcázar, Victoria,Morán, Joaquín R.
supporting information, p. 1297 - 1303 (2015/03/05)
Several bifunctional organocatalysts based on a carbazole scaffold containing a chiral amine and a synthetic oxyanion-hole have been synthesized and successfully applied to the synthesis of the Hajos-Wiechert and Wieland-Miescher ketones (up to 99% ee). Both enamine activation and H-bonding donor ability of these catalysts were evaluated by preparing catalysts differing in the nature of the amine [(R,R)-cyclohexanediamine or l-proline], the H-bond donor functional group (sulfonamide or amide) and the number of NH bonds. Modeling studies and an X-ray structure fully support the obtained results.