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Eg5 is a kinesin motor protein that is responsible for bipolar spindle formation and plays a crucial role during mitosis. Loss of Eg5 function leads to the formation of monopolar spindles, followed by mitotic arrest, and subsequent cell death. Several cell-permeable small molecules have been reported to inhibit Eg5 and some have been evaluated as anticancer agents. We now describe the design, synthesis, and biological evaluation of photoswitchable variants with five different pharmacophores. Our lead compound Azo-EMD is a cell permeable azobenzene that inhibits Eg5 more potently in its light-induced cis form. This activity decreased the velocity of Eg5 in single-molecule assays, promoted formation of monopolar spindles, and led to mitotic arrest in a light dependent way.

(Chemical Equation Presented) We have developed an environmentally benign synthetic approach to nucleophilic substitution reactions of alcohols that minimizes or eliminates the formation of byproducts, resulting in a highly atom-efficient chemical process. Proton- and metal-exchanged montmorillonites (H- and Mn+-mont) were prepared easily by treating Na +-mont with an aqueous solution of hydrogen chloride or metal salt, respectively. The H-mont possessed outstanding catalytic activity for nucleophilic substitution reactions of a variety of alcohols with anilines, because the unique acidity of the H-mont catalyst effectively prevents the neutralization by the basic anilines. In addition, amides, indoles, 1,3-dicarbonyl compounds, and allylsilane act as nucleophiles for the H-mont-catalyzed substitutions of alcohols, which allowed efficient formation of various C-N and C-C bonds. The solid H-mont was reusable without any appreciable loss in its catalytic activity and selectivity. Especially, an Al3+-mont showed high catalytic activity for the α-benzylation of 1,3-dicarbonyl compounds with primary alcohols due to cooperative catalysis between a protonic acid site and a Lewis acidic Al3+ species in its interlayer spaces.

Triphenylmethanols (or their ethers) bearing phenylazo groups react with trifluoroacetic acid to give deeply colored solutions of the tritylium ions 7(+) - 9(+), (RC6H4N=NC6H4)nC(+)(C6H5)3-n (R = H, Me, Cl, NO2, MeO, H2N, Me2N), whose long wavelengths VIS absorptions and lowfield 1H-NMR signals are consistent with the existence of through-conjugated ?-electron systems.After addition of trifluoromethanesulfonic acid significant hypsochromic shifts of the VIS bands as well as additional proton deshieldings in the 1H-NMR spectrum are observed, which are in accordance with the formation of proximally azo-protonated phenylazotritylium ions 7(+)*H(+), 8(+)*2H(+), and 9(+)*3H(+), (RC6H4N=N(+)H-C6H4)nC(+)(C6H5)3-n.Fully analogous acid-strength-dependent ionisation/protonation reactions result for the overall p-substituted ions 17(+), 18(+), (RC6H4N=NC6H4)C(+)(C6H4R')2 (R,R' = Me, MeO, Me2N), as well as for the azobistritylium system 10(2+), (C6H5)2C(+)C6H4N=NC6H4C(+)(C6H5)2, and its azoxy derivative 11(2+).The linearly extended bis- and trisazo systems 19(+), 22(+), MeC6H4N=N(C6H4N=N)1,2C6H4C(+)(C6H5)2 and the (phenylazo)styryl system 20(+), MeC6H4N=NC6H4CH=CHC6H4C(+)(C6H5)2 in trifluoroacetic acid do not show any significant color changes relativ to the corresponding monofunctional parent types.In trifluoromethanesulfonic acid, however, compounds 19(+), 22(+) exhibit the usual bathochromic shifts of the longest wavelenght VIS absorption accompanying the increasing protonation of the polyazo system.In the case of the tritylium ions containing azomethine bridges, 24(+), only for the methoxy derivative 24b(+) indications for the existence of the conjugatively extended tritylium system (MeOC6H4N=CHC6H4)C(+)(C6H5)2 are found.The amide derivatives 26(+)-29(+), on the other hand, presents no clues for the existence of through-conjugated systems of the kind ArC(OH)=NC6H4C(+)Ar2 and ArN=C(OH)C6H4C(+)Ar2, respectively.

Heating N-phenylacetyldiphenylamine in a sealed tube at 360 deg C gave rise to carbon monoxide, bibenzyl, toluene, stilbene, diphenylmethane, aniline, carbazole, N-benzylcarbazole, acridine, 9-phenylacridine, 4-aminotriphenylmethane, diphenylamine, p-benzyldiphenylamine, and o-aminodiphenylmethane.A similar result was also obtained on heating N-benzyldiphenylamine, with the exception of carbon monoxide.Such results in addition to those obtained from photolysis of N-phenylacetyldiphenylamine are interpreted in terms of a free-radical mechanism.