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941.
R. Rajesh 《Tetrahedron letters》2010,51(44):5845-5848
An efficient approach to the synthesis of a new class of tetraspiro-bispyrrolidines and tetraspiro-bisoxindolopyrrolidines has been accomplished through 1.3-dipolar cycloaddition reaction. The reported method is a one-pot, three component reaction, that is, run under solvent-free microwave conditions. 相似文献
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Susagna Ricart Dr. Josep M. Moretó Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(30):9193-9202
From a practical synthetic point of view, the nickel‐mediated carbonylative cycloaddition of alkynes and allyl halides is a straightforward method for obtaining the cyclopentane skeleton in high yields and with controlled stereochemistry, especially when considering the efficiency of the intermolecular version of the reaction. The efforts to make the previously stoichiometric process catalytic in nickel, after experimental mechanistic observations, are reported herein. The unexpected intervention of iron as a reductant and the isolation of a final dimeric species that exhibits interesting tautomeric behavior are also presented. An extension of the reaction to new substrates has led to the conclusion that, although the steric and electronic effects of the alkyne substituents are generally irrelevant in relation to the adducts and their yields, those of the allylic counterpart may have a significant influence on the outcome of the reaction. However, the presence of the amine moiety in the alkyne completely inhibited the reaction. The feasibility of a multicentered reaction was verified with a triacetylene in which up to 12 bonds were created at once and in good yield. 相似文献
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Nemesio Martinez‐Castro Andrew J. D. Magenau Robson F. Storey 《Journal of polymer science. Part A, Polymer chemistry》2010,48(12):2533-2545
1‐(ω‐Azidoalkyl)pyrrolyl‐terminated polyisobutylene (PIB) was successfully synthesized both by substitution of the terminal halide of 1‐(ω‐haloalkyl)pyrrolyl‐terminated PIB with sodium azide and by in situ quenching of quasiliving PIB with a 1‐(ω‐azidoalkyl)pyrrole. Azide substitution of the terminal halide was carried out in 50/50 heptane/DMF at 90 °C for 24 h using excess azide. The 1‐(ω‐haloalkyl)pyrrolyl‐PIB precursors included 1‐(2‐chloroethyl)pyrrolyl‐PIB, 1‐(2‐bromoethyl)pyrrolyl‐PIB, and 1‐(3‐bromopropyl)pyrrolyl‐PIB. In situ quenching involved direct addition of 1‐(2‐azidoethyl)pyrrole to quasiliving PIB initiated from 5‐tert‐butyl‐1,3‐di(1‐chloro‐1‐methylethyl)benzene (bDCC)/TiCl4 at ?70 °C in hexane/CH3Cl (60/40, v/v). 1H NMR analysis of the quenched product revealed mixed isomeric end groups in which PIB was attached at either C2 or C3 of the pyrrole ring (C2/C3 = 0.40/0.60). SEC indicated the absence of coupled PIB under optimized conditions, confirming exclusive mono‐substitution on each pyrrole ring. 1‐(3‐Azidopropyl)pyrrolyl‐PIB was reacted in modular fashion with various functional alkynes, propargyl alcohol, propargyl acrylate, glycidyl propargyl ether, and 3‐dimethylamino‐1‐propyne, via a Huisgen 1,3‐dipolar cycloaddition (Click) reaction, using Cu(I)Br/N,N,N′,N″,N″‐pentamethyldiethylenetriamine or bromtris(triphenylphosphine)Cu(I) as catalyst. The reactions were quantitative and produced PIBs bearing terminal hydroxyl, acrylate, glycidyl, or dimethylaminomethyl groups attached via exclusively four‐substituted triazole linkages. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 2533–2545, 2010 相似文献