共查询到20条相似文献,搜索用时 15 毫秒
1.
《Journal of organometallic chemistry》1991,406(3):C25-C28
The palladium-catalysed dimerization of isoprene with carbon dioxide is promoted by treatment wiht tributyltin ethoxide and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU). 相似文献
2.
Jacqueline Goddat Partha Datta Arthur A. Grey Jeremy R Carver Rajan N. Shah 《Journal of carbohydrate chemistry》2013,32(6):793-800
Abstract The title compound was prepared by first converting trideuteriomethyl 2,3,4-tri-O-benzyl-β-D-mannopyranoside to a 6-bromo-6-deoxy derivative which on elimination by using DBU (1,8-diazabicyclo[5.4.0]undec-7-ene) or DBN (1,5-diazabi-cyclo[4.3.0]non-5-ene) gave a hex-5-enopyranoside derivative. The deuteroboration of the hex-5-enopyranoside followed by oxidation and subsequent deblocking produced trideuteriomethyl 5-deuterium-β-D-mannopyranoside. 相似文献
3.
The reaction of a variety of aldoximes with perfluoroalkanosulfonyl fluoride in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene(DBU) in dichloromethane smoothly generated the corresponding nitriles in 70%–95% yields. 相似文献
4.
Dorokhov V. A. Vasilyev A. V. Baranin S. V. Afanas"ev O. V. Vorushilov A. S. 《Russian Chemical Bulletin》2002,51(8):1545-1548
2,7-Diaryl-3-cyano-4-methylpyrano[4,3-b]pyridin-5-ones were synthesized by Ni(acac)2-catalyzed condensation of aroylacetonitriles with acetoacetates. The competitive Knoevenagel reaction gave 6-aryl-5-cyano-4-methylpyran-2-ones as by-products. A preparative method for the synthesis of the latter compounds in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) as a catalyst was proposed. 相似文献
5.
CH and CH2 groups attached to a heterocycle and a nitro function were rapidly mono- or difluorinated by reaction with 1-chloromethyl-4-fluoro-1,4-diazoniabicyclo[2,2,2]octane bis-tetrafluoroborate (Selectfluor) in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), preferably with ultrasonic irradiation. 相似文献
6.
1,5-Diazabicyclo[4.3.0]non-5-ene (DBN) and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) react with chloro- and dichloro-phosphines leading to onio- and dionio-substituted phosphines. Similarly, onio-substituted silicon and tin derivatives are prepared; they are used as onio-substituent transfer reagents in the synthesis of a trionio-substituted phosphine. 相似文献
7.
8.
A pH-controlled fluorescence switch based on a core-substituted naphthalenediimide compound (NDI-DBU) was constructed. The novel pentacyclic compound (NDI-DBU) was derived from naphthalenediimide (NDI) and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) in only one synthetic operation, catalysized by CuI. 相似文献
9.
Methine and methylene groups attached to a nitro function and heterocycle (and Ph for CH) were rapidly mono- or di-fluorinated by reaction with 1-chloromethyl-4-fluoro-1,4-diazoniabicyclo[2,2,2]octane bis-tetrafluoroborate (Selectfluor) in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), preferably with ultrasonic irradiation. 相似文献
10.
Yu. B. Ivanova N. Zh. Mamardashvili A. V. Glazunov A. S. Semeikin 《Russian Journal of General Chemistry》2014,84(7):1404-1410
2,3,7,8,12,13,17,18-Octaethyl-5,10,15,20-tetrakis(4-methoxyphenyl)porphyrin has been synthesized, and its acid-base and complexing properties in the systems 1,8-diazabicyclo[5.4.0]undec-7-ene-acetonitrile, acetonitrile-Zn(OAc)2, and 1,8-diazabicyclo[5.4.0]undec-7-ene-acetonitrile-Zn(OAc)2 have been studied by spectrophotometry. Titration of 2,3,7,8,12,13,17,18-octaethyl-5,10,15,20-tetrakis(4-methoxyphenyl)porphyrin with 1,8-diazabicyclo[5.4.0]undec-7-ene is accompanied by successive deprotonation of the pyrrole nitrogen atoms with formation of the corresponding mono- and dianion. The overall acid dissociation constant of the title compound has been determined. The complexation of neutral and doubly deprotonated 2,3,7,8,12,13,17,18-octaethyl-5,10,15,20-tetrakis(4-methoxyphenyl)porphyrin with Zn(OAc)2 has been studied, and kinetic parameters for the formation of the zinc complex according to the molecular and ionic mechanisms have been determined. Extra coordination of 1,8-diazabicyclo[5.4.0]undec-7-ene by the zinc complex of 2,3,7,8,12,13,17,18-octaethyl-5,10,15,20-tetrakis(4-methoxyphenyl)porphyrin. 相似文献
11.
Chang-Eun Yeom 《Tetrahedron》2007,63(4):904-909
A convenient and versatile method was developed for aza-Michael addition using a substoichiometric amount of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU). Various nitrogen nucleophiles were efficiently introduced to α,β-unsaturated carbonyl compounds employing 0.5 equiv of DBU. Furthermore, other heteroatomic nucleophiles could also be introduced successfully under the same reaction conditions. 相似文献
12.
[structure: see text] An unexpected discovery of a novel cyclocondensation reaction of 1,8-diazabicyclo[5.4.0]undec-8-ene (DBU) with activated 1,2-dichloro compounds is described. The 2-aminopyrrole skeleton is generated through the concomitant formation of new nitrogen-carbon and carbon-carbon bonds. A new pentacyclic derivative formed upon the reaction of 2,3-dichloroquinoxaline with DBU exhibits strong fluorescence both in solutions (Phi in hexane = 0.4) and in the solid state. 相似文献
13.
Liu W Lee CH Li HW Lam CK Wang J Mak TC Ng DK 《Chemical communications (Cambridge, England)》2002,(6):628-629
Treatment of 3-(2,4-dimethyl-3-pentyloxy)phthalonitrile (2) with CeCl3 in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) in n-pentanol gives the corresponding metal-free phthalocyanine 3, which unexpectedly traps the oxalic acid in the crystal lattice forming a 1:1 inclusion complex. 相似文献
14.
Abstract
N-Arylquinoline derivatives are obtained in excellent yields by a rapid, easy, and efficient one-pot multicomponent reaction of aromatic aldehydes, 3-arylamino-5,5-dimethylcyclohex-2-enone, and active methylene compounds utilizing 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) as a catalyst in ethanol under microwave irradiation. 相似文献15.
《Tetrahedron letters》2014,55(52):7186-7189
The reaction of α,β-unsaturated ketoximes with fluoroalkanosulfonyl fluorides in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) underwent the Beckmann rearrangement smoothly to afford the corresponding acid-sensitive enamides in moderate to excellent yields, which provides a new efficient method for the preparation of acid-sensitive enamides. 相似文献
16.
An efficient strategy for the synthesis of a variety of 2-mercaptobenzothiazole derivatives has been developed. The reaction proceeded from o-haloaniline derivatives and carbon disulfide via a tandem reaction in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) to afford the corresponding 2-mercaptobenzothiazole derivatives in good to excellent yields. 相似文献
17.
D. N. Bazhin T. I. Gorbunova A. Ya. Zapevalov V. I. Saloutin 《Russian Journal of Organic Chemistry》2009,45(4):491-495
Epoxy(perfluoroalkyl)alkenes were synthesized in one step by reaction of perfluoroalkyl iodides with 2-(allyloxymethyl)oxirane and 2-(oct-7-en-1-yl)oxirane in the presence of sodium dithionite and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) under mild conditions. 相似文献
18.
Golnaz Parhizkar Ahmad Reza Khosropour Iraj Mohammadpoor-Baltork Elahehnaz Parhizkar Hadi Amiri Rudbari 《Tetrahedron》2017,73(11):1397-1406
1-Azabicyclo[3.3.0]oct-3-en-2-one derivatives were synthesized efficiently through the facile cascade reaction of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) or 1,5-diazabicyclo[4.3.0]non-5-ene (DBN) with arylidene azlactones. This research provides a straightforward procedure for the synthesis of a novel class of multicyclic semi-alkaloids which shows good antimicrobial activity. Under catalyst-free, mild, and solventless condition, a wide range of fused tricyclic derivatives was obtained in high yields. 相似文献
19.
Devadas Shamala 《合成通讯》2017,47(2):105-110
A new route for ring transformation has been discovered during the reaction of 4-bromomethylcoumarins with hydroxyl amine in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), leading to the formation of pharmacologically important 1,2-oxazinones in a single step with very high yields. 相似文献
20.
Andrew Madin Christopher J. O'Donnell Taeboem Oh David W. Old Larry E. Overman Matthew J. Sharp 《Angewandte Chemie (International ed. in English)》1999,38(19):2934-2936
A complex molecular reorganization ( 1 → 2 ), a sequential anionic aza-Cope rearrangement and Mannich cyclization, and an unprecedented intramolecular Heck reaction of the tetrasubstituted double bond of a vinylogous carbamate are key steps in a new total synthesis of (±)-gelsemine ( 3 ). MOM=methoxymethyl, DBU=1,8-diazabicyclo[5.4.0]undec-7-ene. 相似文献