Possessing two β-cyclodextrin cavities in close vicinity and a functional linker with good structural variety in a single molecule, bridged bis(β-cyclodextrin)s can significantly enhance the original binding ability and molecular selectivity of native β-cyclodextrin and thus be successfully utilized in drug carriers, solubilizers, catalysis, photochemical materials, etc. This Account describes recent developments in the intramolecular cooperative binding and multiple recognition of bridged bis(β-cyclodextrin)s with functional linkers in solution, as well as their molecular assembly behaviors through the intermolecular cooperative binding. It also gives a description of unique properties and wide applications of bis(β-cyclodextrin)s and their assemblies.

Cooperative Binding and Multiple Recognition by Bridged Bis(β-cyclodextrin)s with Functional Linkers

Reaction of acyl chlorides with organometallic reagents: A banquet table of metals for ketone synthesis

A review. This review describes a concept aimed at rational and maximal structure proliferation. To this end, simple arom. or heterocyclic starting materials, often bulk chems., are converted into all regioisomerically possible polar organometallic intermediates (mostly lithiated species), which then may be combined with any of the countless electrophiles to provide attractive new building particularly functionalized derivs. The practical implementation relies on a set (qtoolboxq) of sophisticated recipes developed by mechanistically guided modification of the two most prominent exchange methods used for the generation of polar organometallic compds.: hydrogen-metal and halogen-metal interconversion. These mutant methods (qold methods in a new outfitq) amplify the existing options for org. synthesis by ensuring max. regioflexibility. At the same time they offer new insight into factors that govern organometallic reactivity and provide hints on how to alter or fine tune this reactivity judiciously. [on SciFinder (R)]

The 2×3 Toolbox of Organometallic Methods for Regiochemically Exhaustive Functionalization

The analysis of the 13C NMR spectra of polycyclic aromatics is discussed briefly. Basic trends of chemical shifts are mentioned, but the emphasis is placed on substituent-induced chemical shifts (SCS). Semi-empirical approaches and regressional analysis are treated. The factors controlling SCS are discussed and steric, mesomeric and π-inductive effects are analysed.



CH, CF, CC, CP and C, Metal coupling constants are investigated and the influence of steric effects, bond order, mesomerism and angle distortions in relation to some of these coupling constants is discussed. Relaxation times are described in a series of compounds. The effects of dissolved oxygen or radicals are shown and the use of T1 as a monitor of molecular tumbling is depicted. The impact of 13C NMR on the understanding of charged aromatic species, both positive and negative ions, is mentioned and new information about reaction intermediates in electrophilic aromatic substitution is outlined. The possibility of using 13C NMR to investigate charge transfer complexes is also discussed. Among other subjects treated are automerization, deuterium exchange and biosynthetic incorporation of labelled materials and, finally, quantitative analysis is briefly touched upon.

13C NMR of polycyclic aromatic compounds. A review

Triazolinediones (TADs) are unique reagents in organic synthesis that have also found wide applications in different research disciplines, in spite of their somewhat “exotic” reputation. In this review, we offer two case studies that demonstrate the possibilities of these versatile and reliable synthetic tools, namely, in the field of polymer science as well as in more recently emerging applications in the field of click chemistry. As the general use of triazolinediones has always been hampered by the limited commercial and synthetic availability of such reagents, we also offer a review of the available TAD reagents, together with a detailed discussion of their synthesis and reactivity. This review thus aims to serve as a practical guide for researchers that are interested in exploiting and further developing the exceptional click-like reactivity of triazolinediones in various applications.

https://biblio.ugent.be/publication/8502315/file/8502332.pdf

Triazolinediones as Highly Enabling Synthetic Tools

Dicyclooctatetraeno[1,2:4,5]benzene dianion and tetraanion. Experimental assessment of extended paratropic vs. restricted diatropic .pi.-electron delocalization

Bond fixation in annulenes. 9. Equalization of ring inversion and bond shifting energetics in 1,2,3,4-tetramethylcyclooctatetraene. Asymmetric synthesis direct resolution, and absolute configuration of the optically active hydrocarbon

Bond fixation in annulenes. 8. Assessment of the ring inversion and bond shifting barriers in 1,2,3-trimethylcyclooctatetraene. Resolution, absolute configuration, and circular dichroic behavior of an [8]annulene hydrocarbon

Bond fixation in annulenes. 7. Direct resolution of chiral cyclooctatetraenes

Bond fixation in annulenes. 6. Equalization of ring inversion and bond shifting energetics in methyl-substituted cyclooctatetraenes. Use of buttressing effects for comparing transition-state geometries

John M. Gardlik

Papers

Dicyclooctatetraeno[1,2:4,5]benzene dianion and tetraanion. Experimental assessment of extended paratropic vs. restricted diatropic .pi.-electron delocalization

Bond fixation in annulenes. 9. Equalization of ring inversion and bond shifting energetics in 1,2,3,4-tetramethylcyclooctatetraene. Asymmetric synthesis direct resolution, and absolute configuration of the optically active hydrocarbon

Bond fixation in annulenes. 8. Assessment of the ring inversion and bond shifting barriers in 1,2,3-trimethylcyclooctatetraene. Resolution, absolute configuration, and circular dichroic behavior of an [8]annulene hydrocarbon

Bond fixation in annulenes. 7. Direct resolution of chiral cyclooctatetraenes

Bond fixation in annulenes. 6. Equalization of ring inversion and bond shifting energetics in methyl-substituted cyclooctatetraenes. Use of buttressing effects for comparing transition-state geometries