135655-33-3Relevant articles and documents
The azomethine ylid strategy in β-lactam synthesis. Application to selenapenams
Brown, Giles A.,Anderson, Kirsty M.,Murray, Martin,Gallagher, Timothy,Hales, Neil J.
, p. 5579 - 5586 (2000)
Using azomethine ylid reactivity available from the β-lactam-based oxazolidinone 1, selenoketones 6a-e react as 1,3-dipolarophiles to give racemic selenapenams 7a-e in a single step. The cycloaddition sequence proceeds with complete control of regiochemistry and the thermodynamically more stable C(3)/C(5) relationship is observed. The selenothiocarboxylate 9a and the selenocarboxylate 9b also function as effective dipolarophiles, but attempts to convert the resulting cycloadducts 10a and 10b to the corresponding selenapenems were unsuccessful. Other selenium-containing dipolarophiles failed to give characterizable cycloadducts. (C) 2000 Elsevier Science Ltd.
Stereoselective synthesis of olefins by a reductive coupling reaction
Hua, Guoxiong,Li, Yang,Slawin, Alexandra M. Z.,Woollins, J. Derek
, p. 1477 - 1480 (2007/10/03)
Ketones and aldehydes are converted to symmetrical and (E)-olefins (1-15) by reaction with 2,4-bis(phenyl)-1,3-diselenadiphosphetane-2,4-diselenide (PhPSe2)2, Woollins' reagent, in refluxing toluene; use of diketones was demonstrated by the reaction of PhC(O)CH2C(O)Ph which gives 1,2,4,5-tetraphenylbenzene (16) in 83% yield. The Royal Society of Chemistry 2007.
Novel reaction of selenobenzophenones with alkyllithiums leading to symmetrical olefins
Okuma, Kentaro,Koda, Gen,Okumura, Seiji,Ohno, Atsuyoshi
, p. 609 - 610 (2007/10/03)
The reaction of selenobenzophenones with alkyllithiums or Grignard Reagents exclusively affords symmetrical tetraarylethylenes as selenophilic products. The reaction might proceed through episelenide (selenirane) intermediates.
Stereochemistry of the [4 + 2] cycloaddition of diarylselenoketones with conjugated dienes
Wilker, Stefanie,Erker, Gerhard
, p. 10922 - 10930 (2007/10/03)
The ylides Ph3P=CAr1Ar2 1a-g (Ar = C6H5, p-C6H4Cl, p-C6H4F, m-C6H4CF3, p-C6H4OCH3, p-C6H4-CH3) were treated with elemental selenium (～80°C) to give the corresponding selenoketones Se=CAr1Ar2 2 by Staudinger-chalcogenation. Their reaction with trans,trans-2,4-hexadiene proceeds completely stereospecifically to yield the 2,2-diaryl-3,6-dihydro-cis-3,6-dimethyl-2H-selenapyrans 3. In contrast, the reactions of the selenoketones 2 with cis,trans-2,4-hexadiene proceeds stereoselectively, also giving the dihydro-cis-dimethyl-2H-selenapyrans 3 as the major products, now admixed with small amounts of the dihydro-trans-dimethyl-2H-selenapyran isomers 4. The [4 + 2] cycloaddition of 2 with cis,trans-2,4-hexadiene proceeds stereospecifically, however, when carried out at a pressure of 12 kbar, now yielding 4 as the major products along with the corresponding tetraarylethenes 8. Along with the results of additional mechanistic studies (determination of solvent and substituent effects) it can be concluded that diarylselenoketones are likely to react by means of a concerted [4 + 2] cycloaddition with very reactive conjugated dienes (such as trans,trans-2,4-hexadiene), whereas a stepwise mechanism, resulting in diene cis/trans-isomerization with subsequent mechanistic "leakage" to the concerted pathway, appears to be preferred when a much less reactive conjugated diene such as cis,trans-2,4-hexadiene is employed. The reaction of the corresponding diarylthioketones 5a-g with trans,trans- and cis,trans-2,4-hexadiene, respectively, shows an analogous behavior.
Isolation, Structure and Reaction of Selenobenzophenones. X-Ray Molecular Structure of 4,4'-Dimethoxyselenobenzophenone and of 4,4-Diphenyl-2,3-diselenabicyclooct-7-ene
Okuma, Kentaro,Kojima, Kazuki,Kaneko, Isao,Tsujimoto, Yoshikazu,Ohta, Hiroshi,Yokomori, Yoshinobu
, p. 2151 - 2160 (2007/10/02)
4,4'-Dimethoxy- 1a and 4,4'-dimethyl-selenobenzophenone 1b could be isolated in moderate yields by the reaction of the corresponding ylides 3 with elemental selenium in benzene at 80 deg C.Their spectral data are described.Attempted isolation of unsubstituted selenobenzophenone afforded only its dimer 5.Compound 1a crystallizes in space group P21/n with unit-cell parameters a = 7.191(3), b = 7.505(4=, c = 24.856(4) Angstroem, β = 90.32(1) deg, Z = 4, R = 0.055.The oxidation and thiation of 4,4'-dimethoxyselenobenzophenone 1a afforded the corresponding benzophenone and thiobenzophenone in good yields.The reaction of compound 1 with cyclopentadiene afforded the corresponding cycloadducts 7 (3,3-diaryl-2-selenabicyclohept-5-enes), whereas bicyclic diselenides 8 (4,4-diaryl-2,3-diselenabicyclooct-7-enes were obtained by using an excess of selenium and a higher temperature.Oxidation of compound 8c gave the corresponding diol 12, aldehyde 13, and diphenylfulvene 11.The reaction of compound 1a with benzenediazonium carboxylate afforded 2,2-bis-(4-methoxyphenyl)-4H-3,1-benzooxaselenin-4-one 17.
Isolation and Reaction of Selenobenzophenones
Okuma, Kentaro,Kojima, Kazuki,Kaneko, Isao,Ohta, Hiroshi
, p. 1053 - 1056 (2007/10/02)
4,4'-Dimethoxy- and 4,4'-dimethylselenobenzophenones could be isolated in moderate yields by the reaction of the corresponding ylides with selenium.Their spectral data are described.The oxidation of these compounds with mCPBA afforded the corresponding benzophenones in good yields.Attempted isolation of unsubstituted selenobenzophenone afforded only its dimer.
