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D N Butler

Publications and source records attributed to D N Butler.

5 recordsLinked to original sources
PubMed2001

A new stabilised form of isobenzofuran, rack-mounted on an alicyclophane.

New stable, crystalline isobenzofurans 9a and 9b linked through the 1,3-positions and incorporated into alicyclophanes have been prepared from the related furanoalicyclophane 5 in three steps (i) addition of benzyne or 4,5-bis(trimethylsilyl)benzyne (ii) hydrogenation of the pi-bond (iii) ejection of ethylene by flash vacuum pyrolysis, and shown to yet retain high 1,3-diene character and form adducts with dienophiles, e.g. dimethyl acetylenedicarboxylate or N-methyl maleimide; the corresponding off-rack 1,3-dimethylisobenzofurans were too unstable for isolation.

Journal Article↗
PubMed2001

Incorporation of a molecular hinge into molecular tweezers by using tandem cycloadditions onto 5,6-dimethylenenorbornene.

Site-selective 1,3-dipolar coupling at the norbornene pi-bond of 5,6-dimethylenenorbornene 1 yields cycloadducts with an end-fused 1,3-diene system which have been reacted with N=N (or C=C) dienophiles to produce ribbon molecules, in which the internal diazacyclohexene (or cyclohexene) subunits are capable of acting as conformational hinges. Direct coupling of 5,6-dimethylenenorbornene with 1,3,4-oxadiazoles or dual coupling with bis(cyclobutene epoxides) afforded bis(1,3-dienes) that diastereoselectively react with dienophiles to produce new, conformationally mobile, molecular tweezers.

Journal Article↗