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Kevin I Booker-Milburn

Publications and source records attributed to Kevin I Booker-Milburn.

10 recordsLinked to original sources
PubMed2005

A practical flow reactor for continuous organic photochemistry.

[reaction: see text] Compact flow reactors have been constructed and optimized to perform continuous organic photochemistry on a large scale. The reactors were constructed from commercially available or customized immersion well equipment combined with UV-transparent, solvent-resistant fluoropolymer (FEP) tubing. The reactors were assessed using the [2 + 2] photocycloaddition of malemide 1 and 1-hexyne forming the cyclobutene product 2 and the intramolecular [5 + 2] photocycloaddition of 3,4-dimethyl-1-pent-4-enylpyrrole-2,5-dione 3 to form the bicyclic azepine 4. The reactors were shown to be capable of producing >500 g of 2 and 175 g of 4 in a continuous 24 h processing period. Due to the facile control of irradiation time, the continuous flow reactor was also shown to be superior to a batch reactor for performing a problematic photochemical reaction on a larger scale.

Journal Article↗
PubMed2004

Remarkably different structures and reaction mechanisms of ketoreductases for the opposite stereochemical control in the biosynthesis of BIQ antibiotics.

Two ketoreductases, RED1 and RED2, are involved in the biosynthesis of actinorhodin in Streptomyces coelicolor A3(2) and dihydrogranaticin in S. violaceoruber Tu22, respectively. They are responsible for the stereospecific reductions of the bicyclic intermediate to give (S)- or (R)-DNPA, although there is no similarity between their amino acid sequences. Biotransformation using synthetic analogous substrates revealed that the substrate specificities are quite different. Homology modelling studies and site directed mutagenesis showed remarkable differences in three-dimensional structures and catalytic mechanisms between RED1 and RED2.

Alcohol Oxidoreductases↗
PubMed2004

Rapid access to azepine-fused oxetanols from alkoxy-substituted maleimides.

[reaction: see text] UV irradiation of alkoxy-substituted N-alkenylmaleimides induces a sequence involving a [5 + 2] cycloaddition followed by a Norrish-Yang cyclization. The resulting highly strained alkylidene oxetanol-fused azepines are formed in good yield and with high diastereoselectivities

Journal Article↗
PubMed2003

Synthesis of the reported structure of pogostol and a total aynthesis of (+/-)-kessane without the use of protecting groups.

[reaction: see text] A short racemic synthesis of kessane from 4-hydroxy-4-methyl-2-cyclohexenone is described using a route that also resulted in the synthesis of the reported structure of pogostol. The key step involves an Fe(III)-mediated tandem radical ring-expansion/cyclization of the cyclopropylsilyl ether 9. No protecting groups are used in the entire sequence. Comparison of the NMR data of synthetic pogostol to that in the literature indicates that the structure originally proposed is incorrect.

Journal Article↗
PubMed2003

Ritter-type reactions of N-chlorosaccharin: a method for the electrophilic diamination of alkenes.

[reaction: see text] N-Chlorosaccharin has been shown to undergo electrophilic Ritter-type reactions with alkenes in acetonitrile. The resulting labile beta-chloro sulfonylamidines can be ring-opened and cyclized to imidazolines. Overall this provides a one pot method for the electrophilic diamination of alkenes. Competing aziridine formation as well as allylic chlorination are also observed depending on the nature of the alkene used.

Acetonitriles↗