- Bio-based crotonic acid from polyhydroxybutyrate: synthesis and photocatalyzed hydroacylation
-
A novel thermolytic distillation process was developed to depolymerize polyhydroxybutyrate (PHB) for the selective production of crotonic acid. The conditions adopted (170 °C, 150 mbar) were applied to pure PHB and PHB-enriched bacteria containing 60 and 30% of PHB, giving a recovery of crotonic acid of 92, 78 and 58%, respectively. The high efficiency of the developed process poses the basis for a drop-in production of bio-based crotonic acid, whose versatility as a platform chemical has been investigated through a photochemical approach. The photocatalytic addition (promoted by tetrabutylammonium decatungstate - TBADT) of aliphatic and aromatic aldehydes to crotonic acid took place under solar-simulated light irradiation. TBADT triggered thein situformation of valuable acyl radicals from the corresponding aldehydes, thus inducing the desired hydroacylationviaradical conjugate addition. Notably, the functionalization took place in a satisfactory yield quite independently of the adopted sample of crotonic acid (whether commercial or bio-based).
- Fagnoni, Maurizio,Galletti, Paola,Jorea, Alexandra,Parodi, Adriano,Ravelli, Davide,Samorì, Chiara,Torri, Cristian
-
supporting information
p. 3420 - 3427
(2021/05/21)
-
- Structure-activity relationships in carboxamide derivatives based on the targeted delivery of radionuclides and boron atoms by means of peripheral benzodiazepine receptor ligands
-
The structure-activity relationship studies on 2-quinolinecarboxamide peripheral benzodiazepine receptor (PBR) ligands have been refined with the aim of using these ligands as carriers of radionuclides and boron atoms. Some new ligands show enhanced affinity and steroidogenic activity with respect to reference compound 1 and are interesting candidates for radiolabeling and PET studies. Moreover, carborane derivative 3q, representing the first example of PBR ligand bearing a carborane cage, can be useful to explore an alternative mechanism in BNCT.
- Cappelli, Andrea,Mohr, Galla Pericot,Gallelli, Andrea,Giuliani, Germano,Anzini, Maurizio,Vomero, Salvatore,Fresta, Massimo,Porcu, Patrizia,Maciocco, Elisabetta,Concas, Alessandra,Biggio, Giovanni,Donati, Alessandro
-
p. 3568 - 3571
(2007/10/03)
-
- THERAPEUTIC AGENT FOR DIABETES
-
A therapeutic agent for diabetes, which comprises a compound of the formula [I] wherein Xis a group of the formula wherein R4and R5are the same or different and each is a hydrogen atom, an optionally substituted alkyl having 1 to 5 carbon atoms and the like, and R6is a hydrogen atom or an amino-protecting group; R1is an optionally substituted alkyl having 1 to 5 carbon atoms, an optionally substituted alkenyl having 2 to 6 carbon atoms and the like, R2is a hydrogen atom, an optionally substituted alkyl having 1 to 5 carbon atoms and the like, R2' is a hydrogen atom, and R3is an optionally substituted alkyl having 1 to 5 carbon atoms and the like, a prodrug thereof, a pharmaceutically acceptable salt thereof, a hydrate thereof and a solvate thereof. The compound of the present invention shows superior blood sugar decreasing action on the state of hyperglycemia, but does not affect the blood sugar when it is in the normal range or in the hypoglycemic state, which means that it is free of serious side effects such as hypoglycemia. Therefore, the compound of the present invention is useful as a therapeutic drug for diabetes and also useful as a preventive of the chronic complications of diabetes.
- -
-
-
- PREPARATION AND REACTIONS OF SOME 2-THIENYL AND 3-THIENYL PYRIDAZINONES AND PYRIDAZINES
-
The preparation and reactions of some pyridazinone derivatives with 2- and 3-thienyl substituents are described.Precursor 4-oxobutanoic acids Ar2COCH2CH(Ar1)CO2H (Ar1=Pb, Ar2=2-thienyl and Ar1=2-thienyl, Ar2=Pb) were obtained by addition of HCN to the chalcones Ar1CH=CHCOAr2 followed by acid hydrolysis of the resulting nitrile.Nitriles, ArCOCH(CH3)CH2CN were prepared by the Michael-Stetter reaction and converted via the acids to the 4,5-dihydropyridazin-3(2H)-ones.Two methods wereused to obtain pyridazin-3(2H)-ones viz oxidation of the 4,5-dihydro derivatives with selenium dioxide and base-catalyzed condensation of methanal or aryl aldehydes at the 4-position of the 4,5-dihydro compound.
- Powell, Paul,Sosabowski, Michael H.
-
p. 1840 - 1852
(2007/10/03)
-
- AZO ANIONS IN SYNTHESIS. PT 1. t-BUTYLHYDRAZONES AS ACYL-ANION EQUIVALENTS
-
The lithium salts of aldehyde t-butylhydrazones react with electrophiles (aldehydes, ketones, alkyl halides, crotonates) to form C-trapped t-butylazo-compounds; tautomerisation and hydrolysis gave α-hydroxy ketones, ketones, and γ-keto esters in good yield, thereby providing a convenient new acyl-anion equivalent.Reaction of these lithium salts with aldehydes and ketones, followed by elimination provided a new route to azo alkenes.
- Baldwin, Jack E.,Adlington, Robert M.,Bottaro, Jeffrey C.,Kolhe, Jayant N.,Perry, Matthew W. D.,Jain, Ashok U.
-
p. 4223 - 4234
(2007/10/02)
-
- THE DOUBLE SIMMONS-SMITH REACTIONS VIA SILATROPIES
-
The cyclopropanation of ethyl 3-trimethylsiloxy-2-alkenoates with the Simmons-Smith reagent, followed by ring cleavage and hydrolysis with an alkali solution, gave the corresponding 3-methyl-4-oxoalkanoic acids and 5-oxoalkanoic acids.
- Saigo, Kazuhiko,Yamashita, Takashi,Hongu, Akinori,Hasegawa, Masaki
-
p. 715 - 722
(2007/10/02)
-
- Michael Additions of Hydrazones for Carbon-Carbon Bond Formation
-
The lithium salts of t-butyl- and trityl-hydrazones react with methyl crotonate to form C-trapped azo-esters and similar products were observed from a thermal ene-reaction of aldehyde t-butylhydrazones with methyl acrylate or acrylonitrile, and aldehyde phenylhydrazones with methyl acrylate; these products can be diverted into synthetically useful γ-keto-esters, γ-keto-nitriles, saturated esters, γ-alkyl-2-pyrrrolidones, and γ-amino-esters.
- Baldwin, Jack E.,Adlington, Robert M.,Bottaro, Jeffrey C.,Jain, Ashok U.,Kolhe, Jayant N.,et al.
-
p. 1095 - 1096
(2007/10/02)
-
- Friedel-Crafts Acylation with 2-Methyl- or2-Benzylbutanedioic Anhydride
-
The AlCl3-catalyzed acylation of benzene with 2-methylbutanedioic anhydride afforded mixture of 3-benzoyl-2-methylpropanoic acid and 3-benzoylbutanoic acid.The intramolecular acylation of 2-benzylbutanedioic anhydride in the presence of AlCl3 gave a mixtu
- Hashimoto, Iwao
-
p. 3219 - 3220
(2007/10/02)
-