21732-13-8Relevant academic research and scientific papers
Au(I) Catalyzed Synthesis of Densely Substituted Pyrazolines and Dihydropyridines via Sequential Aza-Enyne Metathesis/6π-Electrocyclization
Sugimoto, Kenji,Kosuge, Shuto,Sugita, Takae,Miura, Yuka,Tsuge, Kiyoshi,Matsuya, Yuji
supporting information, p. 3981 - 3985 (2021/05/26)
A gold(I) autotandem catalysis protocol is reported for the de novo synthesis of densely substituted pyrazolines and dihydropyridines from the corresponding imine derivatives in a highly regioselective fashion via a one-pot aza-enyne metathesis/6π-electrocyclization sequence. The substituents on the nitrogen atom of the imine perfectly control the reaction pathways from the pivotal 1-azabutadiene intermediate; thus, carbazates were converted into pyrazolines via 6π-electrocyclization of α,β-unsaturated hydrazones, while aryl imines provided dihydropyridines via 6π-electrocyclization of 3-azahexatrienes.
Mn(III)-mediated phosphinoylation of aldehyde hydrazones: Direct “one-pot” synthesis of α-iminophosphine oxides from aldehydes
Bian, Xue-Wei,Zhang, Ling,Shoberu, Adedamola,Zou, Jian-Ping
supporting information, (2021/04/02)
A “one-pot” strategy for the straightforward Mn(III)-mediated phosphinoylation of aldehyde hydrazones with diphenylphosphine oxide to furnish α-iminophosphine oxides is described. This mild and practical method allows the direct use of aldehydes as substrates in one pot to generate the hydrazones, which are then engaged “in situ” by the phosphorus reagent in the presence of Mn(OAc)3 oxidant. Thus, the requisite isolation of the hydrazones is not needed in this operation. Conducted mechanistic experiments implicate a pathway involving phosphorus-centered radicals.
Gold-catalyzed three-component spirocyclization: A one-pot approach to functionalized pyrazolidines
Wagner, Bernd,Hiller, Wolf,Ohno, Hiroaki,Krause, Norbert
supporting information, p. 1579 - 1583 (2016/02/10)
An efficient, highly atom economic synthesis of hitherto unknown spirocyclic pyrazolidines in a one-pot process was developed. The gold-catalyzed three-component coupling of alkynols, hydrazines and aldehydes or ketones likely proceeds via cycloisomerization of the alkynol to an exocyclic enol ether and subsequent [3 + 2]-cycloaddition of an azomethine ylide. A library of 29 derivatives with a wide range of functional groups was synthesized in up to 97% yield. With this new method, every position in the final product can be substituted which renders the method ideal for applications in combinatorial or medicinal chemistry.
I2 mediated synthesis of 5-substituted-3-methyl/benzyl-1,3,4-oxadiazol-2(3H)-ones via sequential condensation/oxidative cyclization and rearrangement
Patel, Shyam Sunder,Chandna, Nisha,Kumar, Shreemoyee,Jain, Nidhi
, p. 5683 - 5689 (2016/07/06)
A simple and efficient iodine-assisted protocol for the synthesis of 5-substituted-3-methyl/benzyl-1,3,4-oxadiazol-2(3H)-ones has been developed. The reaction involves a sequential condensation followed by tandem oxidative cyclization and rearrangement of
Metal-Free Synthesis of 1,3,4-Oxadiazoles from N′-(Arylmethyl)hydrazides or 1-(Arylmethyl)-2-(arylmethylene)hydrazines
Shang, Zhenhua,Chu, Qianqian,Tan, Sheng
, p. 1032 - 1040 (2015/03/30)
An efficient and versatile metal-free synthesis of 1,3,4-oxadiazoles from N′-(arylmethyl)hydrazides or 1-(arylmethyl)-2-(arylmethylene)hydrazines through oxidative dehydrogenation is reported. A range of 2,5-disubstituted 1,3,4-oxadiazoles were prepared by treating N′-(arylmethyl)hydrazides with (diacetoxyiodo)benzene in acetonitrile or by treating 1-(arylmethyl)-2-(arylmethylene)hydrazines with [bis(trifluoroacetoxy)iodo]benzene in methyl tert-butyl ether. Aldehyde N-acylhydrazones and aldazines were initially generated in situ as intermediates.
Base-catalyzed N -N bond cleavage of hydrazones: Synthesis of α-amino ketones
Tang, Hai-Tao,Zhou, Yun-Bing,Zhu, Yu,Sun, Hong-Chao,Lin, Min,Zhan, Zhuang-Ping
supporting information, p. 1278 - 1281 (2014/05/06)
An efficient Cs2CO3-promoted synthesis of α-amino ketones using hydrazines, aldehydes, and α-haloketones as starting materials through a cascade condensation/nucleophilic substitution/N -N bond cleavage route is developed. The carbonyl group plays a key role in this novel N -N bond cleavage process. Breaking good: A novel method of base-catalyzed N -N bond cleavage of hydrazones has been discovered. A variety of α-amino ketones was synthesized using hydrazines, α-haloketones, and benzaldehyde as starting materials through a cascade condensation/ nucleophilic substitution/N -N bond cleavage sequence.
Novel synthesis, characterisation and antitumour activity of dimethyl-3,6-di(aryl)-1,4-dihydro-1,2,4,5-tetrazine-1,4-dicarboxylates
Lv, Lu-Ping,Zhou, Xiao-Feng,Shi, Hai-Bo,Gao, Jian-Rong,Hu, Wei-Xiao
, p. 368 - 370 (2014/07/08)
A series of new dimethyl-3,6-di(aryl)-1,4-dihydro-1,2,4,5-tetrazine-1,4- dicarboxylates were synthesised through an intermolecular cyclisation reaction of methyl N'-(a-chloro-substituted benzylidene) hydrazinecarboxylate and triethylamine. Their 1,4-dihyd
Chiral 1,3,4-oxadiazol-2-ones as highly selective FAAH inhibitors
Patel, Jayendra Z.,Parkkari, Teija,Laitinen, Tuomo,Kaczor, Agnieszka A.,Saario, Susanna M.,Savinainen, Juha R.,Navia-Paldanius, Dina,Cipriano, Mariateresa,Lepp?nen, Jukka,Koshevoy, Igor O.,Poso, Antti,Fowler, Christopher J.,Laitinen, Jarmo T.,Nevalainen, Tapio
supporting information, p. 8484 - 8496 (2013/12/04)
In the present study, identification of chiral 1,3,4-oxadiazol-2-ones as potent and selective FAAH inhibitors has been described. The separated enantiomers showed clear differences in the potency and selectivity toward both FAAH and MAGL. Additionally, the importance of the chirality on the inhibitory activity and selectivity was proven by the simplification approach by removing a methyl group at the 3-position of the 1,3,4-oxadiazol-2-one ring. The most potent compound of the series, the S-enantiomer of 3-(1-(4-isobutylphenyl)ethyl) -5-methoxy-1,3,4-oxadiazol-2(3H)-one (JZP-327A, 51), inhibited human recombinant FAAH (hrFAAH) in the low nanomolar range (IC50 = 11 nM), whereas its corresponding R-enantiomer 52 showed only moderate inhibition toward hrFAAH (IC50 = 0.24 μM). In contrast to hrFAAH, R-enantiomer 52 was more potent in inhibiting the activity of hrMAGL compared to S-enantiomer 51 (IC 50 = 4.0 μM and 16% inhibition at 10 μM, respectively). The FAAH selectivity of the compound 51 over the supposed main off-targets, MAGL and COX, was found to be >900-fold. In addition, activity-based protein profiling (ABPP) indicated high selectivity over other serine hydrolases. Finally, the selected S-enantiomers 51, 53, and 55 were shown to be tight binding, slowly reversible inhibitors of the hrFAAH.
Gold-catalyzed three-component annulation: Efficient synthesis of highly functionalized dihydropyrazoles from alkynes, hydrazines, and aldehydes or ketones
Suzuki, Yamato,Naoe, Saori,Oishi, Shinya,Fujii, Nobutaka,Ohno, Hiroaki
supporting information; experimental part, p. 326 - 329 (2012/02/15)
Polysubstituted dihydropyrazoles were directly obtained by a gold-catalyzed three-component annulation. This reaction consists of a Mannich-type coupling of alkynes with N,N′-disubstituted hydrazines and aldehydes/ketones followed by intramolecular hydroa
An efficient solid-phase synthesis of 3-substituted and 3,3-disubstituted 1,2-dialkylpyrazolidine-3,5-diones
He, Rongjun,Lam, Yulin
experimental part, p. 2182 - 2186 (2009/02/01)
An efficient and regioselective procedure for the synthesis of di-, tri- and fully-substituted pyrazolidine-3,5-diones on a solid-phase format is described. Microwave irradiation provided significant rate enhancement in this protocol. To demonstrate the v
