Brase, Julia

[["dc.bibliographiccitation.firstpage","1467"],["dc.bibliographiccitation.issue","10"],["dc.bibliographiccitation.journal","Synlett"],["dc.bibliographiccitation.lastpage","1469"],["dc.contributor.author","Nuske, H."],["dc.contributor.author","Brase, S."],["dc.contributor.author","de Meijere, Armin"],["dc.date.accessioned","2018-11-07T09:58:40Z"],["dc.date.available","2018-11-07T09:58:40Z"],["dc.date.issued","2000"],["dc.description.abstract","Palladium-catalyzed substitutions on primary and secondary 3,3-dimethylcyclopropenylmethyl carbonates 6a-OR, readily prepared by reaction of 3,3-dimethylcyclopropenyllithium with formaldehyde and subsequent acylation with methyl or benzyl chloroformate, with dimethylmalonate enolates and bissulfonyl-stabilized carbanions occurred regioselectively to give derivatives 12-16 in good yields (43-81%). The reaction of the tertiary acetate 6c-Me gave a mixture of the regioisomeric products 17 (43%) and 18 (27%)."],["dc.identifier.isi","000089803400024"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/37412"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Georg Thieme Verlag"],["dc.relation.issn","0936-5214"],["dc.title","New cyclopropyl building blocks for organic synthesis, Part 61 - Catalyzed nucleophilic substitution on cyclopropenylmethyl esters - Reactions via a 1,2-methano-pi-allylpalladium intermediate"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","2350"],["dc.bibliographiccitation.issue","10"],["dc.bibliographiccitation.journal","Chemistry - A European Journal"],["dc.bibliographiccitation.lastpage","2369"],["dc.bibliographiccitation.volume","8"],["dc.contributor.author","Nuske, H."],["dc.contributor.author","Brase, S."],["dc.contributor.author","Kozhushkov, Sergei I."],["dc.contributor.author","Noltemeyer, M."],["dc.contributor.author","Es-Sayed, M."],["dc.contributor.author","de Meijere, Armin"],["dc.date.accessioned","2018-11-07T10:29:48Z"],["dc.date.available","2018-11-07T10:29:48Z"],["dc.date.issued","2002"],["dc.description.abstract","Bicyclopropylidene (1) was found to surpass even methyl acrylate (17a) in its rate of undergoing carbopalladation with aryl- or alkenylpalladium species. leading to substituted allylidenecyclopropanes 5, 7 and 10, mostly in high yields (37 - 78%). These dienes and cross-conjugated trienes react in a Diels-Alder mode with dienophiles to give spiro[2.5]octenes 18a-Ph, 18b-Ph and 18a-Vin, respectively, in good yields (89, 69 and 65%). The overall transformation can be achieved as a one-pot three-component reaction with a variety of dienophiles to furnish the domino Heck-Diels-Alder products 18 regioselectively in most cases in good to very high yields (49-100%). The reaction of I with iodobenzene (2-Ph) and 17a gave 18a-Ph in virtually quantitative yield-also on a gram scale-using, only 1 mol% of catalyst, and even bromobenzene (22) gave 18a-Ph in 59% yield. Bicyclopropylidene (1). in the presence of palladium acetate/triphenylphosphane underwent rearrangement to allylidenecyclopropane (5-H), which in turn dimerized (73%) in the absence of other reaction partners, or could be trapped by diethyl fumarate (17c) to give the Diels-Alder adduct 18c-H in 45% yield. The coupling of oligoiodobenzenes with I and subsequent cycloaddition could he extended to a multicomponent reaction. In this way, 1.4-diiodobenzene (37). 1 and an alkyl acrylate gave the products 38 of a twofold Heck-Diels-Alder reaction in up to 87% yield, 1,3,5-triiodobenzene (39) reacted in up to 72% yield and ultimately 1,2,4,5-tetraiodobenzene (41) gave the fourfold domino Heck-Diels-Alder product 42 in 47% isolated yield, in a single operation in which 12 new carbon-carbon bonds were formed."],["dc.identifier.doi","10.1002/1521-3765(20020517)8:10<2350::AID-CHEM2350>3.0.CO;2-E"],["dc.identifier.isi","000175771300017"],["dc.identifier.pmid","12012419"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/43722"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Wiley-v C H Verlag Gmbh"],["dc.relation.issn","0947-6539"],["dc.title","New highly efficient three-component domino Heck-Diels-Alder reaction with bicyclopropylidene: Rapid access to spiro[2.5]oct-4-ene derivatives"],["dc.type","review"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1745"],["dc.bibliographiccitation.issue","9"],["dc.bibliographiccitation.journal","Pure and Applied Chemistry"],["dc.bibliographiccitation.lastpage","1756"],["dc.bibliographiccitation.volume","72"],["dc.contributor.author","Meijere, Armin de"],["dc.contributor.author","Kozhushkov, Sergei I."],["dc.contributor.author","Spath, T."],["dc.contributor.author","Seebach, M. von"],["dc.contributor.author","Lohr, S."],["dc.contributor.author","Nuske, H."],["dc.contributor.author","Pohlmann, T."],["dc.contributor.author","Es-Sayed, M."],["dc.contributor.author","Brase, S."],["dc.date.accessioned","2018-11-07T10:32:37Z"],["dc.date.available","2018-11-07T10:32:37Z"],["dc.date.issued","2000"],["dc.description.abstract","Bicyclopropylidene (4), now readily available in preparatively viable quantities, is evolving as a useful C-6 building block for organic synthesis due to its enhanced reactivity at the C-H, the C=C, as well as both types of C-C single bonds. Monosubstituted derivatives are accessible by deprotonation/electrophilic substitution. Di- and tetrasubstituted bicyclopropylidenes are best made by copper-mediated reductive dimerization of bromolithiocarbenoids. The 1,3-dipolar cycloadducts of nitrones rearrange to spirocyclopropanated piperidones, palladium-catalyzed codimerizations with acrylates occur with opening of one of the rings to yield precursors to bicyclo[3.3.0]octene and bicyclo[5.3.0]decene skeletons. Silicon-heteroatom bonds can be added across the double bond of 4 under palladium catalysis just like across a C=C triple bond, and carbopalladation of the double bond in 4 occurs more rapidly than that in an acrylate. A variety of new three-component reactions of 4 with alkenyl as well as aryl halides and dienophiles have been developed and extended to be carried out in a combinatorial sense, even on a polymer support, with an additional dimension added in the cleavage step. Most of the reported reactions of bicyclopropylidene (4) proceed with good to excellent yields."],["dc.identifier.isi","000166578600024"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/44389"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Int Union Pure Applied Chemistry"],["dc.publisher.place","Res triangle pk"],["dc.relation.conference","13th International Conference on Organic Synthesis (ICOS-13)"],["dc.relation.eventlocation","WARSAW, POLAND"],["dc.relation.issn","0033-4545"],["dc.title","Bicyclopropylidene. A unique tetrasubstituted alkene and versatile C-6-building block for organic synthesis"],["dc.type","conference_paper"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dspace.entity.type","Publication"]]