<b>Equilibria in Halogen-Lithium Interconversions</b>

Applequist, Douglas E.; O’Brien, David F.

doi:10.1021/ja00889a021

Cited by 148 publications

(48 citation statements)

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“…Materials: Commercially available solutions of BuLi (1 m in hexane), tBuLi (1.5 m in pentane), and LiAlH 4 (1 m in THF) were used as received. Phenyllithium, [42] neopentyllithium, [43] cyclopentyllithium, [44] (Z)-b-bromostyrene, [37] and pentacarbonyl-[1-(3-furyl)-1-methoxymethylidene]-chromium (7) [45] were prepared according to literature procedures. (Z)-or (E)-2-Phenylethenyllithium were preformed by addition at À80 8C of 2 equiv tBuLi to (Z)…”

Section: Methodsmentioning

confidence: 99%

Asymmetric Dearomatization of the Furan Ring Promoted by Conjugate Organolithium Addition to (Menthyloxy)(3‐furyl)carbene Complexes of Chromium

Barluenga

Nandy

Laxmi

et al. 2003

Chemistry A European J

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The sequential low-temperature addition reaction of an organolithium compound and methyl triflate to (menthyloxy)(3-furyl)carbene complexes of chromium and tungsten proceeded with excellent regioselectivity (1,4-addition) and diastereoselectivity (2,3-trans disposition of the nucleophile and electrophile groups) to afford new 2,3-disubstituted (2,3-dihydro-3-furyl)carbene complexes. In addition, a high degree of diastereofacial selectivity was achieved by employing alkenyllithium compounds. After detachment of both the metal fragment and the chiral auxiliary group, trisubstituted 2,3-dihydrofuran derivatives containing a quaternary stereogenic center at the C3 position were obtained. The characterization, including X-ray crystallography, of a novel type of stable four-membered chelate (eta(2)-alkene)tetracarbonylcarbene complex of chromium is also reported.

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Section: Methodsmentioning

confidence: 99%

Asymmetric Dearomatization of the Furan Ring Promoted by Conjugate Organolithium Addition to (Menthyloxy)(3‐furyl)carbene Complexes of Chromium

Barluenga

Nandy

Laxmi

et al. 2003

Chemistry A European J

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“…Separate traps placed three minutes before and after this 6 minute period showed negligible iodine activity. The main product expected in reaction (6) is iodocyclopropane; ^s was synthesized following the procedure outlined by APPLEQUIST and O'BRIEN [18] and was eluted midway through the 6 minute trapping period. The results summarized in Table 2 are the ratios of the count rates for each isotope associated with the €3115*1 compared to the CH3*I.…”

Section: Methodsmentioning

confidence: 99%

The Spin States of lodocarbene Produced from the Reactions of Fission lodine with Methane

Kikuchi

Church

1973

Radiochimica Acta

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One of the chemical reactions of fission-produced iodine, (*I), with gaseous methane is to form an excited State of methyl iodide, (CH3*I]+. This species can undergo unimolecular decomposition to form iodocarbene. CH*I, which can be chemically scavenged with ethylene. It is postulated that the iodocarbene is formed in the triplet and singlet spin states, and that these chemically react in a manner similar to methylene and the other halocarbenes. In order to determine the relative energies of the two spin states, the reactions of CH*I have been studied as a function of pressure both with and without oxygen. It is concluded that ^CH*I, made primarUy by independently produced fission iodine, is the more excited species. Conversely, the 'CH*I, made via the iodine which has undergone 0~-decay, is the lower energy or ground State species. ZusammenfassungEine der chemischen Reaktionen von durch Spaltung erzeugtem Jod (*J) mit Methangas ist die Bildung eines angeregten Zustands von Methyljodid [CH3*J1. Diese Art kann durch einmolekulare Zersetzung in Jodcarben CH*J übergehen, das sich chemisch mit Äthylen einfangen läßt. Es wird postuliert, daß das Jodcarben im Triplett-und im Singlettspinzustand gebildet wird und daß diese Zustände chemisch ähnlich wie Methylen und andere Halogencarbene reagieren. Um die relativen Energien dieser beiden Spinzustände zu bestimmen, sind die Reaktionen von CH*J in Abhängigkeit vom Druck sowohl mit als auch ohne Sauerstoff untersucht worden. Es wird geschlossen, daß ^CH*J, das vor allem durch unabhängig erzeugtes Spaltjod erzeugt wurde, die stärker angeregte Art ist. Umgekehrt ist das 'CH*J, das über das Jod gebildet wurde, das einen /3~-Zerfall durchlaufen hat, die niederenergetische Art oder die Art im Grundzustand. Resume

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“…This clean exchange therefore led to the development of the intramolecular carbolithiation reactions of saturated alkyllithium derivatives [3]. When the exchange is con- ducted using a less reactive organolithium, an equilibrium favoring the more stable organolithium is rapidly established [108]. Therefore, the isomerization of 6-iodo-1-hexene to (iodomethyl)cyclopentane in a variety of solvents with either MeLi or PhLi, was achieved [109].…”

Section: Intramolecular Carbometallation Reactionsmentioning

confidence: 99%