J. William Suggs

Synthesis and DNA crosslinking ability of a dimeric anthramycin analog

Abstract Linked analogs of the DNA binding antibiotic anthramycin are made via nucleophilic aromatic substitution followed by reduction-cyclization. The linked compounds protect DNA from restriction endonucleases and reversibly crosslink DNA.

Directed cleavage of carbon―tin bonds by palladium

Abstract The ligands 8-(trimethylstannyl)methylquinoline, n-Bu 3 Sn(CH 2 ) 3 NMe 2 and Ph 3 Sn(CH 2 ) 3 ,NMe 2 react with (C 6 H 5 CN) 2 PdCl 2 to give five-membered palladium chelates. in which the nitrogen atom was able to direct palladium insertion into a specific carbon—tin bond. The X-ray crystal structure of the simple chelate [(Me 2 N(CH 2 ) 3 )PdCl] 2 is presented.

Synthesis and structure of anthramycin analogs via hydride reduction of dilactams

Hydride reduction of pyrrolo[1,4]benzodiazepine-5,10-diones to carbinolamines is possible if a sufficiently electron-withdrawing group is present on the aromatic ring; the X-ray structure of one such product is given.

Hydrocarbon oxidations with chromyl trifluoroacetate

Abstract Chromyl trifluoroacetate oxidizes hydrocarbons. Including polyolefin polymers, to give predominately alcohols and ketones. The reaction is extremely rapid. A solution of n-hexane, for example, is oxidized upon mixing at −50°.

Structure of the simple lithium chelate (LiCH2CH2CH2NMe2)4

Abstract The structure of (LiCH2CH2CH2NMe2)4 was determined by single-crystal X-ray difffraction at −100°C. The crystal was monoclinic, space group P2/n, a 9.659(2), b 7.007(1), c 18.896(5) A, β 97.61 (2)°. The structure consisted of a tetrahedron of lithium atoms with each face bridged by carbon. The conformation of the five-membered lithium chelate ring was essentially the same as that found for a palladium chelate of the same ligand.

Facile hydrolysis and formation of amide bonds by N-hydroxyethylation of α-amino acids

Abstract The C-terminal amides of α-amino acids are readily hydrolyzed at 25° and pH 7 when the N-terminus is N-hydroxyethylated, with one or two hydroxyethyl groups. The reaction proceeds via cyclization to a morpholinolactone (2) which is rapidly hydrolyzed by water. In the presence of equimolar amounts of amines or amino acid derivatives, 2 reacts in H2O without condensing agents to form a new peptide bond.

Preparation, structure and spectroscopic studies of the palladium mercaptides Pd8(S-nPr)16 and Pd6(S-nPr)12

Abstract Various palladium salts react with n-propane thiol to form a mixture of the cyclic mercaptides Pd8(S-nPr)16 (I) and the known Pd6(S-nPr)12 (II). I is described as an octagonal toroid, containing a planar ring of palladium atoms, each being bridged by four mercapto groups in approximately square planar geometry. The pendant n-propyl groups radiate outward in approximately axial and equatorial orientations with respect to the ring, which was also observed in solution by 1H and 13C NMR. Crystal data: space group C2/c, a=22.251(15), b=27.623(6), c=14.621(17) A, β=116.35°(4), V=8053(4) A3. Least-squares refinement based on 3103 observed reflections led to an R value of 0.078. I and II failed to complex any appropriate guest species, as evidenced by the UV-Vis spectra. I was found to have a reversible oxidation wave at E/2= 0.77 V, and a irreversible oxidation wave of 1.09 V. II displayed two irreversible peak potentials at 0.77 and 1.09 V. In each case, the waves were one electron processes, in which the reversibility was not enhanced at low temperatures.

Reactivity patterns in the reactions of [Rh(CO)2Cl]2 with chelating ketones

Abstract A survey is made of the reactions of chelating ketones and aldehydes with [(CO) 2 RhCl] 2 . With the enolizable ketone 8-quinolinyl benzyl ketone a rhodium(I)-vinyl alcohol π-complex forms, whose crystal structure was determined (C 18 H 13 NO 2 ClRh, monoclinic space group C 2/ c , a 14.531(3), b 18.038(3), c 15.257(3) A, β 111.48(1)°, V 3721 A 3 , Z = 8, final R w 4.16%). The non-enolizable ketone 8-quinolinyl phenyl ketone gives oxygen atom transfer to CO, producing CO 2 and a 1,3-dirhodiametallacyclobutane complex. Oxygen atom transfer is also seen from 8-nitroquinoline to give a chelating nitroso ligand. Finally 8-quinoline carboxaldehyde undergoes CH activation followed by loss of H 2 to give a dimeric acylrhodium(II), whose crystal structure was determined (C 26 H 12 N 2 O 8 Cl 4 Rh 4 , orthorhombic space group Pccn , a 9.466(5), b 13.648(9), c 24.124(14) A, V 3119 A 3 , Z = 4 final R w 5.68%).

Use of phosphorothioate analogs of poly(dA-dT) · poly(dAdT) to study steroidal-diamine induced conformational change in poly(dA-dT) · poly(dA-dT)

31P NMR DNA phosphorothioate Steroidal diamine DNA conformation

Nicking of supercoiled DNA via metal radical generated from photolysis of species containing metal-metal bonds

Abstract The photoactivated metal-dimers, Pd 2 (CH 3 NC) 6 2+ and Pt 2 (CH 3 NC) 6 2+ are shown to nick supercoiled DNA in a light-dependent reaction. The photoactivated metal dimers, Pd 2 (MeNC) 6 2+ and Pt 2 (MeNC) 6 2+ , nick DNA in a light-dependent reaction.