Linked Life Data

12929436

Source:http://linkedlifedata.com/resource/pubmed/id/12929436

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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2003-8-21
pubmed:abstractText
The 2-tert-butyl-3-phenylphosphirenylium ion 13 is formed in abundance in the gas phase from 1-chloro-1H-phosphirene 6 upon 70 eV electron ionization. Collision-induced dissociation (CID) and ion-molecule reactions followed by CID of the product ions were performed via pentaquadrupole mass spectrometry to probe the structure and reactivity of 13 towards representative nucleophiles and dienes. Under CID conditions, 13 produces a variety of fragment ions mainly via dissociation processes that are preceded by isomerizations. In ion-molecule reactions, 13 reacts readily with ethers, sulfides, pyridine and aniline to form hitherto unknown oxonium, sulfonium and azonium ions via nucleophilic attack at phosphorus. With butadiene, isoprene, 1-acetoxybutadiene, and with Danishefsky's diene (1-methoxy-3-silyloxybuta-1,3-diene), 13 undergoes [4 + 2+] cycloaddition at phosphorus to generate novel P-spiro bicyclic phosphonium ions. With butadiene and isoprene, a second [4 + 2] cycloaddition occurs which generates P-spiro tricyclic phosphonium ions. Whereas 13 also reacts readily with 1-acetoxybutadiene via[4 + 2+] cycloaddition, most of the nascent P-spiro cycloadducts are unstable and dissociate by the loss of either a neutral ketene or acetic acid molecule. B3LYP/6-31G(d,p) calculations were performed to gain insight into the structures of the product ions. The present study constitutes the first successful attempt to unravel the chemistry of 13, a unique 2 pi-Hückel phosphirenylium ion for which no direct solution chemical reactivity data are as yet available. The present findings also create a parallel with the solution reactivity of 1-halo-1H-phosphirenes and 1-triflato-1H-phosphirenes as precursors to phosphirenylium ions.
pubmed:language
eng
pubmed:journal
pubmed:status
PubMed-not-MEDLINE
pubmed:month
Jan
pubmed:issn
1477-0520
pubmed:author
pubmed:issnType
Print
pubmed:day
21
pubmed:volume
1
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
395-400
pubmed:year
2003
pubmed:articleTitle
Gas phase chemistry of the 2-tert-butyl-3-phenylphosphirenylium cation: novel onium ions by nucleophilic attack at phosphorus and de novo P-spiro bicyclic phosphonium ions via [4 + 2+] cycloaddition with dienes.
pubmed:affiliation
State University of Campinas-UNICAMP, Institute of Chemistry, CP6154 13083-970 Campinas, São Paulo, Brazil.
pubmed:publicationType
Journal Article