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1.
Vijaya Gracias Alan F. Gasiecki Joel D. Moore Irini Akritopoulou-Zanze Stevan W. Djuric 《Tetrahedron letters》2006,47(50):8977-8980
A general method for the preparation of diaza-spirocycles is reported. This method used an olefin metathesis in order to construct the desired spirocyclic framework. Beginning with commercially available protected amino ketones, this strategy ultimately produced pharmacologically relevant diaza-scaffolds in an efficient and high-yielding process. 相似文献
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Yu Gui Gu Xiaolin Zhang Richard F. Clark Stevan W. Djuric Zhenkun Ma 《Tetrahedron letters》2004,45(15):3051-3053
An intramolecular 1,3-dipolar cycloaddition of azomethine ylide, generated in situ via the reaction of C12-glycinate derivative of macrolide with formaldehyde, provided a novel tricyclic macrolide. The high stereoselectivity of this [2+3] reaction was achieved by introducing a suitable directing group at C-6 position of macrolide. 相似文献
5.
Synthesis of fused imidazo-pyridine and -azepine derivatives by sequential van Leusen/Heck reactions
Fused imidazo-pyridine and -azepine derivatives were synthesized using a sequential van Leusen/intramolecular Heck protocol. The combination of a multicomponent reaction followed by an intramolecular carbon-carbon bond forming reaction generates heterocycles of significant molecular complexity from readily available starting materials in just two steps. 相似文献
6.
Stevan W. Djuri Richard B. Herbert Frederick G. Holliman 《Journal of heterocyclic chemistry》1985,22(5):1425-1428
A novel procedure for the chemoselective reduction of 2-acyl-1H-indole-3-carboxaldehydes has been developed. Low temperature lithium triethylborohydride reduction affords the indol-2-yl carbinol whilst sodium cyanoborohydride reduction in acetic acid affords the 3-hydroxymethyl analogs. Both processes are high yield, and provide access to intermediates of potential utility for indole alkaloid synthesis. 相似文献
7.
James R. Gord Stevan R. Horning Joseph M. Wood R. Graham Cooks Ben S. Freiser 《Journal of the American Society for Mass Spectrometry》1993,4(2):145-151
We report studies of the internal energy deposited during activation of mass-selected ions through electron-ion collisions. Characteristic fragmentations of the molecular ion of limonene and W(CO) n/+ (n = 1–6) indicate that electron-induced dissociation in a Fourier transform ion cyclotron resonance mass spectrometer proceeds via multiple collisions and that the average internal energy deposited during the activation process can be selected to be similar to that associated with electron-impact ionization. Control of the degree of ion excitation through selection of the electron energy, flux, and interaction time with the ions of interest is demonstrated, and advantages of this promising activation technique are discussed. 相似文献
8.
Irini Akritopoulou-Zanze Vijaya Gracias Joel D Moore Stevan W Djuric 《Tetrahedron letters》2004,45(17):3421-3423
We report the synthesis of novel fused isoxazoles and isoxazolines by employing an unprecedented Ugi/INOC synthetic sequence. The coupling of the Ugi multicomponent reaction with the intramolecular N-oxide cyclization provides access to unique heterocyclic ring systems in two steps from easily available starting materials in moderate to good overall yields. 相似文献
9.
1,3,4-Oxadiazoles can be rapidly and efficiently synthesized from a variety of carboxylic acids and acid hydrazides in one simple step. The use of commercially available PS-PPh3 resin combined with microwave heating delivered the product 1,3,4-oxadiazoles in high yields and purities. 相似文献
10.
Benzoxazoles or benzimidazoles can be rapidly and efficiently synthesized from a variety of carboxylic acids with 2-aminophenols or 1,2-phenylenediamines in one simple step, respectively. The use of commercially available PS-PPh3 resin combined with microwave heating delivered a variety of benzoxazoles and benzimidazoles in high yields and purities. 相似文献