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101.
David K O'DellKenneth M Nicholas 《Tetrahedron》2003,59(6):747-754
A representative o-nitroenone (Z=O) was cyclized by reduction with CO and [CpFe(CO)2]2 (Fp2) as the catalyst to give the corresponding 4-quinolone. In contrast, Baylis-Hillman adducts derived from o-nitrobenzaldehydes were cyclized to N-formylindolines and indoles under the same conditions. 相似文献
102.
The synthesis of the title compounds starting with the chemoselective dehydrogenation of 3-[2-(3,4-dihydro-1-naphthalenyl)ethyl]imidazolidine-2,4-diones has been described. 相似文献
103.
Cyclization were occurred via the coupling reactions of some mercuric chloride derivatives of sydnone with LiPdCl3-CuCl2. A unique six-membered ring, 3,3′-ethylene-4,4′-bissydnone, was obtained by the cyclization reation of 1,2-di[3-(4-chloromercuric)sydnonyl]ethane. However, the seven-membered 3,3′-trimethylene-4,4′-bissydnone and 1,3-di[3-(4-chloro)sydnonyl]-propane were obtained from the corresponding mercuric chlroide of sydnone. Onyl substitution reaction took place when 4,4′-di[3-(4-chloromercuric)sydnonyl]biphenyl, 4,4′-di[3-(4-chloromercuric)sydnonyl]benzene, di(p-[3-(4-chloromercuric)sydnonyl]-phenyl}methane and, di(p-[3-(4-chloromercuric)sydnonyl]phenyl]ether were treated using the same process. 相似文献
104.
A general method for the synthesis of 5-substituted indolizidines based on intramolecular cyclization oftrans- andcis-2-allyl-6-R-1,2,3,6-tetrahydropyridines, obtained from pyridine and triallylborane, has been elaborated. The closure of the
five-membered ring is carried out by hydroboration-oxidation followed by cyclization of the resulting δ-amino alcohols in
the presence of the Ph3P−CBr4−Et3N system. (Pr2BH)2 and Pr3B are used as the hydroborating reagents, and H2O2 in an acid medium is used for the oxidation of 2-[3-(dipropylboryl]-Δ2-piperideines formed. This method has been used for the synthesis of two natural alkaloids: indolizidine 209D (cis-5-hexylindolizidine) and itstrans-isomer were prepared fromcis- andtrans-2-allyl-6-hexyl-1,2,3,6-tetrahydropiridine, respectively; indolizidine 167B andtrans-5-propylindolizidine were synthesized fromcis- andtrans-2,6-diallyl-1,2,3,6-tetra-hydropyridine, respectively.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 971–979, May, 1998. 相似文献
105.
D. L. Lipilin A. M. Churakov Yu. A. Strelenko V. A. Tartakovsky 《Russian Chemical Bulletin》2007,56(8):1566-1568
Treatment of 2-(tert-butyl-NNO-azoxy)anilines with phosgene at 20 °C was proposed as a novel route to 1,2,4-benzotriazin-3(4H )-one 1-oxides. This method involves a new reaction, viz., an intramolecular interaction of the tert-butyl-NNO-azoxy group with a C-electrophile (leading to the formation of the N(2)—C(3) bond of the triazine ring) followed by elimination
of the tert-butyl group. Complete assignment of the signals in the 1H and 13C NMR spectra of the compounds obtained was performed.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1507–1509, August, 2007. 相似文献
106.
Z. G. Aliev O. P. Krasnykh A. N. Maslivets Yu. S. Andreichikov L. O. Atovmyan 《Russian Chemical Bulletin》1997,46(3):543-545
Thermal decarbonylation of 1-benzyl-4,5-dibenzoyl-2,3-dihydropyrrole-2,3-dione yields benzoyl[N-benzyl(phenylglyoxalimidoyl)]ketene. The latter undergoes intramolecular cyclization to 3-benzoyl-5-phenyl-2,3,4,5-tetrahydrofuro[3,2-c]isoquinolin-2-one. Which is oxidized to 3-benzoyl-5-phenyl-2H,4H-furo[3,2-c]isoquinolin-2-one under the reaction conditions. The crystal and molecular structure of the title compound was studied by
X-ray structural analysis.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 563–565, March, 1997. 相似文献
107.
Synthesis of new diheteroarylcarbazoles: a facile and simple route of 3,6-di(pyrazol-4-yl)carbazoles
Ramu Meesala 《Tetrahedron letters》2006,47(43):7557-7561
A short and facile route to the synthesis of new 3,6-di(pyrazol-4-yl)carbazoles is reported. Dipyrazolylcarbazoles were synthesized in two steps from 3,6-diacetylcarbazoles through a Vilsmeier reaction which led to the formation of carbazolyl-β-chlorovinyl aldehydes, followed by cyclization with hydrazine hydrate. The reaction of the Vilsmeier reagent with hydrazones of diacetylcarbazoles yielded the corresponding pyrazole dicarbaldehydes in good yields. 相似文献
108.
Hiroki FurutaToyohisa Takase Hisafumi HayashiRyoji Noyori Yuji Mori 《Tetrahedron》2003,59(49):9767-9777
An efficient method has been developed for the synthesis of trans-fused tetrahydropyrans with angular methyl groups adjacent to the ring oxygen. The procedure involves the coupling reaction of a sulfonyl-stabilized oxiranyl anion with an appropriate triflate followed by 6-endo cyclization, and is effective for the construction of 6/6- and 6/7/6-cyclic ether ring systems with sterically congested 1,3-diaxial methyl groups. 相似文献
109.
A stereocontrolled linear synthesis of the ABCDEF-ring system of yessotoxin and adriatoxin, diarrhetic shellfish toxins, is described. Iterative application of a tetrahydropyran synthesis by reaction of the alkylation of a sulfonyl-stabilized oxiranyl anion followed by 6-endo cyclization of a 4,5-epoxy alcohol led to the synthesis of the trans-fused hexacyclic ether system, and the seven-membered E ring was constructed by ring expansion reaction. 相似文献
110.
Iván Bélai 《Tetrahedron letters》2003,44(40):7475-7477
An efficient and versatile method has been developed for the synthesis of 1-aminohydantoin derivatives which can be substituted at all the possible positions of the hydantoin ring. The starting materials are aldehydes, ketones, carboxylic acids and hydrazides as well as isocyanates readily available from commercial sources. The semicarbazide-type reaction product of an N-acyl-N′-(1-cyanoalkyl)hydrazine, obtained from the above materials by methods known from the literature, and an isocyanate is cyclized in the presence of a basic catalyst to yield 1-acylamino-4-imino-2-oxoimidazolidine derivatives whose acid catalyzed hydrolysis leads to 1-aminohydantoin derivatives in good to excellent yields. The last two steps are carried out in a single reaction medium. 相似文献