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Philip Hodge

Publications and source records attributed to Philip Hodge.

7 recordsLinked to original sources
PubMed2005

Michael reactions carried out using a bench-top flow system.

The Michael reaction between methyl 1-oxoindan-2-carboxylate and methyl vinyl ketone was achieved successfully by pumping solutions of the reactants in toluene through a fluid bed of Amberlyst A21 at 50 degrees C. The use of a fluid bed reactor is attractive as it allows gel-type beads, i.e. the type of bead used in most studies of polymer-supported (PS) organic reactions, to be used satisfactorily in a flow system. When polymer-supported cinchonidine was used in place of Amberlyst A21, the Michael product was obtained in high yield with an enantiomeric excess (ee) of 51%. This % ee is comparable to that achieved when the reaction was catalysed by cinchonidine itself.

Butanones↗
PubMed2005

Langmuir-Blodgett films of preformed polymers containing biphenyl groups.

Polymers containing liquid crystal groups have been studied previously as waveguides, and they have been deposited as spacer materials with various chromophores to form alternating films However, only a few members of this group of materials have been studied in any detail, and very little structural information has been obtained so far. Therefore, a more detailed examination of these materials as mono- and multilayers was undertaken. A new group of materials including the same mesogenic group, polymeric sulfones, was also studied. The polymers gave steep isotherms with high collapse pressures, indicating good packing of the monolayers, and could be deposited to form thick multilayers. X-ray diffraction showed that an ordered multilayer was formed, and the effects of the polymers chemical nature on the structure of the LB films are discussed. It appears that the dominant factor in monolayer structure is the nature of the polymer backbone rather than that of the liquid crystal side chains, which play a secondary role.

Biphenyl Compounds↗
PubMed2005

Biosynthesis of the allene (-)-marasin in Marasmius ramealis.

[1-14C]-E-dehydromatricaria methyl ester and dimethyl [1-14C]-deca-4,6,8-triyne-1,10-dioate are incorporated into the allene (-)-marasin in Marasmius ramealis without scrambling of the 14C label. This and the levels of the incorporations (0.8% and 4.9% respectively) strongly suggests that the above esters, or close relatives, can be converted directly into (-)-marasin in M. ramealis, and that the diyne-allene moiety in this latter compound arises by the rearrangement, under enzymic control, of an alkyltriyne moiety.

Acetylene↗
PubMed2003

Towards more chemically robust polymer-supported chiral catalysts: alpha,alpha-diphenyl-L-prolinol based catalysts for the reduction of prochiral ketones with borane.

alpha,alpha-Diphenyl-L-prolinol derivatives with para-bromo substituents in either one or both of the phenyl rings are easily bound to crosslinked polystyrene beads containing phenylboronic acid residues by Suzuki couplings. By using extended reaction periods boronic acid residues that do not take part in the couplings are simply lost by hydrolysis. The polymer-supported (PS) alpha,alpha-diphenyl-L-prolinols were used to catalyse reductions of several prochiral ketones with borane in tetrahydrofuran at 22 degrees C. The expected secondary alcohols were obtained in high chemical yields and ees were generally in the range 79-97%. One PS catalyst was recycled 14 times without loss of stereochemical performance.

Boranes↗
PubMed2003

Organic synthesis using polymer-supported reagents, catalysts and scavengers in simple laboratory flow systems.

The use of appropriate combinations of polymer-supported reagents, catalysts and/or scavengers is a powerful approach, both for the synthesis of single organic compounds and for parallel syntheses. A further stage of development is the use of such reactants in flow systems. So far, it has been shown that a variety of flow formats afford excellent chemical yields and, where relevant, excellent enantiomeric excesses. The supports have a longer lifetime than in batch systems. 'Flow cascades' promise to be important in future.

Catalysis↗
PubMed2002

Towards more chemically robust polymer-supported chiral catalysts for the reactions of aldehydes with dialkylzincs.

N-Methyl-alpha,alpha-diphenyl-L-prolinol derivatives with para-bromo substituents in one or both of the phenyl rings are easily bound to crosslinked polystyrene beads containing phenylboronic acid residues using Suzuki reactions. When the products were used as catalysts for the reactions of aldehydes with diethylzinc in toluene at 20 degrees C, the alcohols were produced in chemical yields >90% and with ees of upto 94%. The better of the two supported catalysts gave ees only 0-9% lower than those obtained with the corresponding soluble catalyst. One of the supported catalysts was recycled successfully nine times.

Alcohols↗