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861.
Knappwost-Gieseke C Nerenz F Wartchow R Winterfeldt E 《Chemistry (Weinheim an der Bergstrasse, Germany)》2003,9(16):3849-3858
The cycloaddition of spirobutenolide 3 to the homochiral cyclopentadiene 1 at 6.5 kbar leads exclusively to cycloadduct 5. Subsequent Diels-Alder or Michael additions again favour the cyclohexenone double bond; this perfect chemo- regio- and face selectivity was employed for a short and efficient approach to the wistarin framework. 相似文献
862.
Treatment of lead(II) bromide with phenylmagnesium bromide at low temperature furnishes yellow crystals of the ionic compound [BrMg(THF)5]+ [:Pb(PbPh3)3]- which, upon X-ray crystallographic analysis, reveals three stretched Pb-Pb bonds and Pb-Pb-Pb angles of about 93 degrees. 相似文献
863.
Oxidation of dodeca-substituted porphyrin 1 in the presence of NaNO2/TFA and air afforded benzoylbiliverdin 3 in 77% yield; under similar conditions the Ni(II)-porphyrin 2 was mainly nitrated at a cyclohexenyl ring; key X-ray structures are presented. 相似文献
864.
Frank I 《Angewandte Chemie (International ed. in English)》2003,42(14):1569-1571
865.
866.
In this paper we report the synthesis of cyclic diynes of the general formula mX2n. The letters m and n indicate the lengths of chains between two C triple bond C-X units where X indicates S, Se, or Te. The lengths of the bridges vary between m=4-8 and n=2-6. Structural investigations by means of X-ray diffraction reveal for most systems a chair-like conformation in the solid state. For 5S(2)2, 5S(2)3, 7S(2)5, 5Se(2)2 and 5Te(2)3 tubular structures were encountered. These structures can be traced back to weak XX or weak C-Hpi interactions. 相似文献
867.
The dinuclear copper(I) complex [Cu(2)L(1)(CH(3)CN)(2)](ClO(4))(2) (1, L(1) = 3,6,9,17,20,23-hexaazatricyclo[23.3.1.1]triaconta-1(29),2,9,11(30),12(13),14,16,23,25,27-decaene) has been structurally characterized. As previously described, intramolecular ligand hydroxylation (at the aromatic ring) was observed when 1 was reacted with dioxygen. A stopped-flow analysis of the reaction of 1 with dioxygen under different conditions did not allow a "dioxygen intermediate" to be spectroscopically detected. Detailed NMR and electrochemical data on 1 are also presented and evaluated for the first time. No copper(II) complexes of L(1) could be characterized due to hydrolysis of the compounds. In contrast, complex 2-differing from 1 only in an increase in the size of the chelate rings-did not undergo intramolecular hydroxylation when it was oxidized. The crystal structure of 2 is also described. 相似文献
868.
Gerritz SW Norman MH Barger LA Berman J Bigham EC Bishop MJ Drewry DH Garrison DT Heyer D Hodson SJ Kakel JA Linn JA Marron BE Nanthakumar SS Navas FJ 《Journal of combinatorial chemistry》2003,5(2):110-117
The high-throughput manual solid-phase parallel synthesis of libraries comprising thousands of discrete samples using pellicular supports (i.e. SynPhase crowns and lanterns) and a suite of novel tools and techniques is described. Key aspects of this approach include the combination of a split-split-split synthesis strategy with spatial encoding to differentiate thousands of crowns, the rapid washing and filtration of up to 48 reaction vessels in parallel, the application of an inexpensive and environmentally friendly technique to remove trifluoroacetic acid from sixteen 96-well plates in parallel, and a high-throughput method for removing cleaved crowns from reusable pin racks. Tens of thousands of discrete samples have been produced in-house using this conceptually and operationally straightforward strategy. 相似文献
869.
French SA Sokol AA Bromley ST Catlow CR Rogers SC King F Sherwood P 《Angewandte Chemie (International ed. in English)》2001,40(23):4437-4440
870.
Rusina O Eremenko A Frank G Strunk HP Kisch H 《Angewandte Chemie (International ed. in English)》2001,40(21):3993-3995