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Enhancing the reactivity of 1,2-diphospholes in cycloaddition reactions


, : Enhancing the reactivity of 1,2-diphospholes in cycloaddition reactions. Beilstein Journal of Organic Chemistry 11: 169-173

Two different approaches have been employed to enhance the reactivity of 1-alkyl-1,2-diphospholes - the introduction of electron-withdrawing groups either at the phosphorus atoms or in the para-position of the arene ring. The alkylation of sodium 1,2-diphospha-3,4,5-triphenylcyclopentadienide with alkyl halides Hal-CH2-R (R = CN, COOEt, OMe, CH2OEt) results in corresponding 1-alkyl-3,4,5-triphenyl-1,2-diphospholes (alkyl = CH2CN (1a), CH2COOEt (1b), CH2OMe (1c), and (CH2)2OEt (1d)), which spontaneously undergo the intermolecular [4 + 2] cycloaddition reactions at room temperature to form the mixture of the cycloadducts, 2a-c, respectively. However the alkylation of sodium 1,2-diphospha-3,4,5-tri(p-fluorophenyl)cyclopentadienide with ethyl iodide leads to stable 1-ethyl-3,4,5-tris(p-fluorophenyl)-1,2-diphosphole (1e), which forms the [4 + 2] cycloadduct 2,3,4,4a,5,6-hexa(p-fluorophenyl)-1-ethyl-1,7,7a-triphospha-4,7-(ethylphosphinidene)indene (2e) only upon heating up to 60 °C. With further heating to 120 °C with N-phenylmaleimide, the cycloadducts 2a-c and 2e undergo the retro-Diels-Alder reaction and form only one product of the [4 + 2] cycloaddition reaction 3a-с, 3e with good yields up to 65%.

US$19.90

PMID: 25815066

DOI: 10.3762/bjoc.11.17


Other references

Karastanev, I.; Dimitrakov, D.; Kostov, K.; Goranov, S., 1979: Malignant, rapidly progressing nephritis in Schönlein-Henoch disease. A case of malignant quickly progressing Henoch-nephritis is described, with a lethal end one and a half month after the initial manifestations. The disease develops with a clinical picture typical for systemic vasculitis, with joint-pain, skin-ras...

Hurley, M.L., 1991: What do the new JCAHO standards mean for you?. Rn 54(6): 42-47

Hoffmann, D.E.; Rothenberg, K.H., 2004: Whose duty is it anyway?: the Kennedy Krieger opinion and its implications for public health research. Journal of Health Care Law & Policy 6(1): 109-147

Maruti, S.S.; Feskanich, D.; Colditz, G.A.; Frazier, A.Lindsay.; Sampson, L.A.; Michels, K.B.; Hunter, D.J.; Spiegelman, D.; Willett, W.C., 2004: Adult recall of adolescent diet: reproducibility and comparison with maternal reporting. Many cancers have long latency periods, and dietary factors in adolescence may plausibly affect cancer occurrence in adulthood. Because of a lack of prospective data, retrospective collection of data on adolescent diet is essential. A 124-item hig...

Barzoi, D.; Apostu, S., 2002: Microbiological food products. The use of microorganisms in the Romanian food industry is described. The first part of the book considers the principal groups of microorganisms which are of importance for the food industry: bacteria, fungi and viruses. Chapters include an intro...

Descottes, B.; Lachachi, F.; Durand-Fontanier, S.; Sodji, M.; Pech de Laclause, B.; Valleix, D., 2001: Laparoscopic treatment of solid and cystic tumors of the liver. Study of 33 cases. Laparoscopic liver surgery is still in its early stages. The aim of this study was to report our experience in the laparoscopic management of solid and cystic liver tumours. From April 1991 to December 1999, 32 patients with various lesions of the...

Petros P.E.P., 1991: Surgery of female incontinence. International Journal of Gynecology & Obstetrics (ABSTR SUPPL): 422

Koka, V.; Huang, X.Ru.; Chung, A.C.K.; Wang, W.; Truong, L.D.; Lan, H.Yao., 2008: Angiotensin II up-regulates angiotensin I-converting enzyme (ACE), but down-regulates ACE2 via the AT1-ERK/p38 MAP kinase pathway. The recent discovery of the angiotensin II (Ang II)-breakdown enzyme, angiotensin I converting enzyme (ACE) 2, suggests the importance of Ang II degradation in hypertension. The present study explored the signaling mechanism by which ACE2 is regul...

Lacey, M.L.; Haimo, L.T., 1994: Cytoplasmic dynein binds to phospholipid vesicles. Cytoplasmic dynein is the putative motor protein for retrograde organelle transport along microtubules in cells and, thus, must be capable of binding to organelle membranes. Such an attachment may occur via receptor proteins or through a direct in...

Barnes, Pj, 1987: Wheat grain lipids and their role in the bread-making process. Recent advances in chemistry and technology of fats and oils edited by RJ Hamilton and A Bhati: 07