- 作 者: "Donohoe, Timothy J."
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Asymmetric Synthesis of the Fully Elaborated Pyrrolidinone Core of Oxazolomycin AOrganic Letters (IF 6.072) Pub Date : 2012-10-12 ,DOI:10.1021/ol302541jTimothy J. Donohoe,Timothy J. C. O’Riordan,Manuel Peifer,Christopher R. Jones,Timothy J. MilesChemistry Research Laboratory, Department of Chemistry, University of Oxford, Mansfield Road, Oxford, OX1 3TA, U.K., and Medicines Research Centre, GlaxoSmithKline, Gunnels Wood Road, Stevenage, SG1 2NY, U.K.The asymmetric synthesis of the key pyrrolidinone core, including a highly elaborated exocyclic carbon chain, of the γ-lactam β-lactone antibiotic oxazolomycin A is described. Principal features include the Birch reduction of an aromatic pyrrole nucleus, a late stage RuO4 catalyzed pyrrolidine oxidation, and a highly diastereoselective organocerium addition to an aldehyde. ...
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Ruthenium‐Catalyzed Isomerization of Terminal Olefins: Applications to SynthesisAngewandte Chemie International Edition (IF 16.823) Pub Date : 2009-01-07 ,DOI:10.1002/anie.200804617Timothy J. Donohoe,Timothy J. C. O'Riordan,Carla P. RosaIn, out, olefin about: A ruthenium hydride complex derived from the Grubbs second‐generation metathesis catalyst has proven to be an efficient catalyst for the selective isomerization of terminal olefins to the corresponding propenyl derivatives (see scheme). This methodology has been applied in a number of syntheses to enable access to complex natural products. Cy=cyclohexyl, Mes=mesityl, MOM=methoxymethyl ...
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Scope of the reductive aldol reaction: application to aromatic carbocycles and heterocycles.Organic & Biomolecular Chemistry (IF 3.89) Pub Date : 2003 Nov 7 ,DOI:Donohoe, Timothy J, House, David, Ace, K WThe reductive aldol reaction of electron deficient aromatic compounds has been investigated and found to be a viable method for carbon-carbon bond formation. Reductions under ammonia and ammonia-free conditions were both capable of facilitating the aldol reaction although the latter showed more scope for reaction with enolisable aldehydes. Moreover, reduction under ammonia-free conditions allowed the ...
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The tethered aminohydroxylation (TA) reaction.Organic & Biomolecular Chemistry (IF 3.89) Pub Date : 2003 Jun 2 ,DOI:Donohoe, Timothy J, Johnson, Peter D, Pye, Richard JSince Sharpless' discovery of the asymmetric aminohydroxylation (AA) reaction, a major challenge for chemists has been to find ways of controlling the regio- and stereochemical outcome of this important reaction. Detailed herein is a review of our novel approach towards gaining reliable and predictable regio- and stereocontrol through the use of a tethered carbamate to promote an intramolecular AA ...
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Scope of the directed dihydroxylation: application to cyclic homoallylic alcohols and trihaloacetamides.Organic & Biomolecular Chemistry (IF 3.89) Pub Date : 2003 Jun 2 ,DOI:Donohoe, Timothy J, Mitchell, Lee, Waring, Michael J, Helliwell, Madeleine, Bell, Andrew, Newcombe, Nicholas JThe synthesis and directed dihydroxylation of a range of cyclic alkenes was investigated. Both homoallylic alcohols and homoallylic trihaloacetamides were found to be efficient directing groups, giving rise to good to excellent levels of remote asymmetric induction with OsO4-TMEDA. Interestingly, in all cases examined, trifluoroacetamides were found to be superior to trichloroacetamides as directing ...
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Directed dihydroxylation of cyclic allylic alcohols and trichloroacetamides using OsO4/TMEDA.The Journal of Organic Chemistry (IF 4.198) Pub Date : 2002 Nov 1 ,DOI:Donohoe, Timothy J, Blades, Kevin, Moore, Peter R, Waring, Michael J, Winter, Jon J G, Helliwell, Madeleine, Newcombe, Nicholas J, Stemp, GeoffreyThe oxidation of a range of cyclic allylic alcohols and amides with OsO4/TMEDA is presented. Under these conditions, hydrogen bonding control leads to the (contrasteric) formation of the syn isomer in almost every example that was examined. Evidence for the bidentate binding of TMEDA to OsO4 is presented and a plausible mechanism described. ...
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The tethered aminohydroxylation (TA) of cyclic allylic carbamates.Journal of the American Chemical Society (IF 16.383) Pub Date : 2002 Nov 6 ,DOI:Donohoe, Timothy J, Johnson, Peter D, Cowley, Andrew, Keenan, MartineThe tethered aminohydroxylation of cyclic allylic carbamates is described using catalytic amounts of potassium osmate. The mechanism of reaction involves formation of an imido-osmium complex which adds intramolecularly to alkenes with complete control of both regio- and stereoselectivity: the formation of syn-aminodiol motifs is now straightforward using this chemistry. Proof of the mechanism was obtained ...
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Synthesis of enantiopure dihydropyranones: aldol-based ring expansion of dihydrofurans.Organic Letters (IF 6.072) Pub Date : 2002 Sep 5 ,DOI:Donohoe, Timothy J, Raoof, Ali, Freestone, Graeme C, Linney, Ian D, Cowley, Andrew, Helliwell, Madeleine[reaction: see text] The stereoselective Birch reduction of 3-methyl-2-furoic acids using a readily available chiral auxilairy is described; by coupling this process to an oxidative cleavage/aldol ring closure sequence we were able to produce highly functionalized and enantiopure dihydropyranones in high yield. This sequence has ample flexibility built into it, either by the use of different electrophiles ...
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Ammonia free partial reduction of aromatic compounds using lithium di-tert-butylbiphenyl (LiDBB).The Journal of Organic Chemistry (IF 4.198) Pub Date : 2002 Jul 1 ,DOI:Donohoe, Timothy J, House, DavidThe reduction of a series of hetero- and carbocyclic aromatic compounds under ammonia free conditions is described. By using LiDBB as a source of electrons, bis(methoxyethyl)amine (BMEA) as a protonating agent, and THF as a solvent, we were able to accomplish reductions more usually performed under Birch type conditions. Moreover, the use of these conditions was further enhanced by the tolerance of ...
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