1567-14-2Relevant articles and documents
Palladium/IzQO-Catalyzed coordination-insertion copolymerization of ethylene and 1,1-disubstituted ethylenes bearing a polar functional group
Yasuda, Hina,Nakano, Ryo,Ito, Shingo,Nozaki, Kyoko
, p. 1876 - 1883 (2018)
Coordination-insertion copolymerization of ethylene with 1,1-disubstituted ethylenes bearing a polar functional group, such as methyl methacrylate (MMA), is a long-standing challenge in catalytic polymerization. The major obstacle for this process is the huge difference in reactivity of ethylene versus 1,1-disubstituted ethylenes toward both coordination and insertion. Herein we report the copolymerization of ethylene and 1,1-disubstituted ethylenes by using an imidazo[1,5-a]quinolin-9-olate-1-ylidene-supported palladium catalyst. Various types of 1,1-disubstituted ethylenes were successfully incorporated into the polyethylene chain. In-depth characterization of the obtained copolymers and mechanistic inferences drawn from stoichiometric reactions of alkylpalladium complexes with methyl methacrylate and ethylene indicate that the copolymerization proceeds by the same coordination-insertion mechanism that has been postulated for ethylene.
Green and Catalytic Synthesis of Dominicalure I, Major Component of the Aggregation Pheromone of Rhyzopertha dominica (Fabricius) (Coleoptera: Bostrichidae)
Dibello, Estefanía,Seoane, Gustavo,Gamenara, Daniela
supporting information, p. 975 - 981 (2015/03/30)
(Chemical Equation Presented). A new concise and efficient catalytic synthesis of dominicalure I, the male-produced aggregation pheromone of the grain borer Rhyzopertha dominica, is herein reported. The synthetic route was designed starting from easily available propanal through an organocatalytic key step and completed with biocatalytic procedures.
Systematic methodology for the development of biocatalytic hydrogen-borrowing cascades: Application to the synthesis of chiral α-substituted carboxylic acids from α-substituted α,β-unsaturated aldehydes
Knaus, Tanja,Mutti, Francesco G.,Humphreys, Luke D.,Turner, Nicholas J.,Scrutton, Nigel S.
supporting information, p. 223 - 233 (2015/02/19)
Ene-reductases (ERs) are flavin dependent enzymes that catalyze the asymmetric reduction of activated carbon-carbon double bonds. In particular, α,β-unsaturated carbonyl compounds (e.g. enals and enones) as well as nitroalkenes are rapidly reduced. Conversely, α,β-unsaturated esters are poorly accepted substrates whereas free carboxylic acids are not converted at all. The only exceptions are α,β-unsaturated diacids, diesters as well as esters bearing an electron-withdrawing group in α- or β-position. Here, we present an alternative approach that has a general applicability for directly obtaining diverse chiral α-substituted carboxylic acids. This approach combines two enzyme classes, namely ERs and aldehyde dehydrogenases (Ald-DHs), in a concurrent reductive-oxidative biocatalytic cascade. This strategy has several advantages as the starting material is an α-substituted α,β-unsaturated aldehyde, a class of compounds extremely reactive for the reduction of the alkene moiety. Furthermore no external hydride source from a sacrificial substrate (e.g. glucose, formate) is required since the hydride for the first reductive step is liberated in the second oxidative step. Such a process is defined as a hydrogen-borrowing cascade. This methodology has wide applicability as it was successfully applied to the synthesis of chiral substituted hydrocinnamic acids, aliphatic acids, heterocycles and even acetylated amino acids with elevated yield, chemo- and stereo-selectivity. A systematic methodology for optimizing the hydrogen-borrowing two-enzyme synthesis of α-chiral substituted carboxylic acids was developed. This systematic methodology has general applicability for the development of diverse hydrogen-borrowing processes that possess the highest atom efficiency and the lowest environmental impact. This journal is
A facile one-pot stereoselective synthesis of trisubstituted (E)-2-methylalk-2-enoic acids from unactivated Baylis-Hillman adducts and a simple access to some important insect pheromones
Das, Biswanath,Chowdhury, Nikhil,Banerjee, Joydeep,Majhi, Anjoy
, p. 6615 - 6618 (2007/10/03)
An efficient one-pot stereoselective synthesis of trisubstituted (E)-2-methylalk-2-enoic acids has been accomplished by treatment of unactivated Baylis-Hillman adducts, 3-hydroxy-2-methylenealkanoates, with Al-NiCl2·6H2O in methanol at room temperature followed by hydrolysis. The method has been applied to the synthesis of three important insect pheromones, (4S,2E)-2,4-dimethyl-2-hexenoic acid, (+)-(S)-manicone and (+)-(S)-normanicone.
Synthetic applications of the Baylis-Hillman reaction: Simple and convenient synthesis of five important insect pheromones
Das, Biswanath,Banerjee, Joydeep,Chowdhury, Nikhil,Majhi, Anjoy,Mahender, Gurram
, p. 876 - 883 (2007/10/03)
A simple and convenient synthesis of five important insect pheromones by means of Baylis-Hillman adducts is described, i.e., of (2E,4S)-2,4-dimethylhex- 2-enoic acid (1), a mandibular-gland secretion of the male carpenter ant in the genus Camponotus, of (+)-(S)-manicone (2) and (+)-(S)-normanicone (3), two mandibular-gland constituents of Manica ants, and of (+)-dominicalure-I (6) and (+)-dominicalure-II (7), two aggregation pheromones of the lesser grain borer Rhyzopertha dominion (F). For the first time, the potential of the Baylis-Hillman chemistry for the stereoselective synthesis of trisubstituted olefins was successfully applied to the synthesis of these pheromone compounds.
HISTONE DEACETYLASE INHIBITORS
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Page 48, (2008/06/13)
The present invention provides histone deacetylase inhibitors of general formula (I), process for the preparation of such compounds and uses of the compounds in medicine.
Process for the preparation of substituted pyrrolidine neuraminidase inhibitors
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, (2008/06/13)
A process for the preparation of neuraminidase inhibitors having structural formula (28) or therapeutically acceptable salts thereof, in which R1 is alkyl, cycloalkyl, cycloalkylalkyl, or arylalkyl; R2 is alkyl, cycloalkyl, cycloalky
Control of regioselectivity by the lone substituent through steric and electronic effects in the nitrosoarene ene reaction of deuterium-labeled trisubstituted alkenes
Adam, Waldemar,Krebs, Oliver,Orfanopoulos, Michael,Stratakis, Manolis
, p. 8395 - 8399 (2007/10/03)
For the ene reaction of 4-nitronitrosobenzene (ARNO) with a variety of primary and secondary lone alkyl-substituted substrates, the twix/twin regioselectivity is constant at about 85:15. In contrast, for the lone tert-butyl group and for lone aryl substituents, the twix regioisomer is obtained exclusively. These regioselectivities have been rationalized in terms of steric interactions and coordination between the enophile and the substrates in the transition states of the first reaction step.
Structure-activity relationships of unsaturated analogues of valproic acid
Palaty,Abbott
, p. 3398 - 3406 (2007/10/02)
The principal metabolite of valproic acid (VPA), 2-ene VPA, appears to share most of VPA's pharmacological and therapeutic properties while lacking its hepatotoxicity and teratogenicity, thus making it a useful lead compound for the development of safer antiepileptic drugs. Analogues of 2-ene VPA were evaluated for anticonvulsant activity in mice using the subcutaneous pentylenetetrazole test. Cyclooctylideneacetic acid exhibited a potency markedly exceeding that of VPA itself with only modest levels of sedation. Potency, as either ED50 or brain concentration, was highly correlated (r > 0.85) with volume and lipophilicity rather than with one of the shape parameters calculated by molecular modeling techniques, arguing against the existence of a specific receptor site. Instead, a role for the plasma membrane in mediating the anticonvulsant effect is suggested.
CC-KUPLUNGEN VON CO2 MIT 1,3-DIENEN AN EISEN(0)-KOMPLEXEN; CARBOXYLATBILDUNG UND FOLGEREAKTIONEN
Hoberg, Heinz,Jenni, Klaus
, p. 193 - 202 (2007/10/02)
1,3-Dienes react with CO2 at ligand-iron(0) systems to η3-allyl carboxylates.The dynamic allylic system is influenced by addition of further ligands such as phosphanes or maleic acid anhydride or acetic acid anhydride.The direction of this infl
