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The dolabellane‐type diterpene dictyoxetane represents a significant challenge to synthetic organic chemistry. Methodology directed towards the total synthesis of naturally occurring (+)‐dictyoxetane is reported. Catalytic asymmetric synthesis of the trans‐hydrindane ring system is achieved through chemoselective deoxygenation of the Hajos‐Parrish ketone. An alternative to the Garst‐Spencer furan annulation is developed for the synthesis of a 2,5‐dimethyl, tetrasubstituted furan, employing a tandem 5‐exo‐dig alcohol to alkyne cyclisation/aromatisation reaction as a key step. The (4+3) cycloaddition reaction of an oxyallyl cation with a tetrasubstituted furan is established on a cyclohexanone‐derived model system, and a range of related (4+3) cycloadditions investigated on a homochiral, trans‐hydrindane‐fused furan, where regio‐ and diastereoselectivity is required for the natural product synthesis. In an alternative (4+2) Diels‐Alder approach, a C2‐symmetric vinyl sulfoxide‐based chiral ketene equivalent is used to prepare oxanorbornenes with the same oxygen bridge stereochemistry found in the 2,7‐dioxatricyclo[4.2.1.03,8]nonane ring system of the natural product. [ABSTRACT FROM AUTHOR]

The reaction of the five-membered C,N-palladacycle [(L)PdCl]2, where LH = 1-methyl-5-phenyl-1H-1,4-benzodiazepin-2(3H)-one, with 1,2-ethanebis(diphenylphosphine), dppe, leads to the formation of the bridged palladacycle. [Pd2L2(μ-dppe)Cl2] 3, which was characterised in solution by 1H and 31P NMR spectroscopy and in the solid state by X-ray crystallography. Complex 3was tested in vitroagainst a number of cell lines. For example, it inhibited K562 leukaemia cells with an IC50value of 4.3 μM (1 h exposure) and displayed cathepsin B inhibitory action with an IC50value of 3 μM. [ABSTRACT FROM AUTHOR]

N-Alkylation of a novel pyridine sensor results in pyridinium salts whose conformations are stabilised by pyridinium cation–π interactions resulting in a fluorescent response that can be used to sense the presence of alkylating agents in solution at low concentration. [ABSTRACT FROM AUTHOR]

Abstract: A library of 1,4-benzodiazepines has been synthesized and evaluated against Trypanosoma brucei, a causative parasite of Human African trypanosomiasis. Benzodiazepines possessing a P2- transporter motif were found to have MIC values as low as 0.78μM. [Copyright &y& Elsevier]

A series of aryiboronates has befell synlhesizeil from the reaction of 2-{2-, (3-, or (4-(bramomethyl)phenyl)-4,4,5,5-tetramethyl-1,3,2-diaxabarolane 1 {1-3} respectively with a range of N-, S-, and O-nucleophiles, using microwave-medialed chemistry. For the synthesis of N- and S-substituted boronates, a supported base, PS-NMM, was With O-nucleophiles, a mixture of tetrabutylammonium bromide, potassium carbonate, and sodium hydroxide was employed. The resulting aminomethyl, mercaptomethyl, or alkoxy-phenoxymethyl-arylboronates were subjected lo microwave-mediated Suzuki Miyanra cuuphng reactions to afford a range of biaryls in moderate to good yields. The X-ray structures of five boronates were determined. [ABSTRACT FROM AUTHOR]

Abstract: 1,1′-Ferrocene biscarboxaldehyde (1) has been prepared and the aldehyde groups were subsequently protected with acetal groups to produce 1,1′-bisacetalferrocene (2). A ring-locked ferrocene was synthesised by further derivatisation of the cyclopentadiene rings at the 2,2′ positions with phosphine substituents to produce 2,2′-bis-(acetal)-1,1′-diphenylphosphinoferrocene (3), which was subsequently coordinated to either a nickel chloride (5) or nickel bromide (6) metal centre. The ring-locked ferrocene complexes produced 2,5′-bis-(acetal)-1,1′-diphenylphosphinoferrocene substitution patterns. The acetal protecting groups of 2,2′-bis-(acetal)-1,1′-diphenylphosphinoferrocene were removed to produce 1,1′-bis-carboxaldehyde-2,2′-diphenylphosphinoferrocene (4). The Cp rings of 1,1′-bisacetalferrocene were also further derivatised at the 2,2′ positions with a silane to produce the ring-locked 1,1′-siloxane-2,5′-bisacetalferrocenophane (7). The acetal protecting groups were removed from this to produce 1,1′-siloxane-2,5′-ferrocenophanecarboxaldehyde (8). For both the phosphine and siloxane electrophiles, the substitution on the Cp rings gives chiral products (obtained as racemic mixtures). Due to the highly regioselective nature of the reaction and diastereoselectivity in the products only C 2-symmetric compounds were observed without the presence of meso diastereoisomers. Subsequent ring-locking forced the Cp rings to rotate, leading to 1,1′-ring-locked ferrocenes with 2,5′-arrangement of the acetal groups (i.e. on opposite faces of the ferrocene unit). [Copyright &y& Elsevier]