Efficient α-methylenation Of Carbonyl Compounds In Ionic Liquids At Room Temperature

The application of several 1-butyl-3-methylimidazolium (BMIM) salt ionic liquids as solvent in the α-methylenation of carbonyl compounds at room temperature is reported. The ionic liquid [BMIM][NTf 2] gave a clean reaction in a short time and good yields of several α-methylene carbonyl compounds. This ionic liquid was reused without affecting the reaction rates or yields over seven runs. © Georg Thieme Verlag Stuttgart.17578Stiger, K.D., Mar-Tang, R., Bartlet, P.A., (1999) J. Org. Chem, 64, p. 8409Weingarten, M.D., Skudlarek, J., Sikorski, J.A., (2006), PCT Int. Appl. WO 2006004903Mori, K., Yajima, A., Takikawa, H., (1996) Liebigs. Ann, p. 891Picman, A.K., (1986) Biochem. Syst. Ecol, 14, p. 255Schmidt, T.J., (1999) Curr. Org. Chem, 3, p. 577Basavaiah, D., Rao, A.J., Satyanarayana, T., (2003) Chem. Rev, 103, p. 811Kagan, H.B., Riant, O., (1992) Chem. Rev, 92, p. 1007Huang, C.G., Chang, B.R., Chang, N.C., (2002) Tetrahedron Lett, 43, p. 2721Clososki, G.C., Milagre, C.D.F., Moran, P.J.S., Rodrigues, J.A.R., (2007) J. Mol. Catal. B: Enzym, 48, p. 70Boehm, H.M., Handa, S., Pattenden, G., Roberts, L., Blake, A.J., Li, W.-S., (2000) J. Chem. Soc., Perkin Trans. 1, p. 3522Takano, S., Inomata, K., Samizu, K., Tomita, S., Yanase, M., Suzuki, M., Iwabuchi, Y., Ogasawara, K., (1989) Chem. Lett, 1283Lappert, M.F., (2005) J. Organomet. Chem, 690, p. 5467Kraus, G.A., Kim, J., (2004) Synthesis, p. 1737Blazejewski, J.C., Anselmi, E., Wernicke, A., Wakselman, C., (2002) J. Fluorine Chem, 117, p. 161Hin, B., Majer, P., Tsukamoto, T., (2002) J. Org. Chem, 67, p. 7365Nadolski, G.T., Davidson, B.S., (2001) Tetrahedron Lett, 42, p. 797Abellán, T., Chinchilla, R., Galindo, N., Guillena, G., Nájera, C., Sansano, J.S., (2000) Eur. J. Org. Chem, p. 2689Hon, Y.S., Chang, F.J., Lu, L., (1994) J. Chem. Soc., Chem. Commun, p. 2041Hon, Y.S., Chang, F.-J., Lu, L., Lin, W.C., (1998) Tetrahedron, 54, p. 5233Hon, Y.S., Chen, H.F., (2007) Tetrahedron Lett, 48, p. 8611Hon, Y.S., Hsieh, C.H., (2006) Tetrahedron, 41, p. 9713Hon, Y.S., Hsieh, C.H., Liu, Y.W., (2005) Tetrahedron, 61, p. 2713Hon, Y.S., Liu, Y.W., Hsieh, C.H., (2004) Tetrahedron, 60, p. 4837For the total synthesis of brevetoxin B (second to last step), see: (a) Nicolaou, K. C.Rutjes, F. P. J. T.Theodorakis, E. A.Tiebes, J.Sato, M.Untersteller, E. J. Am. Chem. Soc. 1995, 117, 1173Nicolaou, K.C., Reddy, K.R., Skokotas, G., Fuminori, S., Xiao, X.-Y., (1992) J. Am. Chem. Soc, 114, p. 7935. , See also: bCrimmins, M.T., Stanton, M.G., Allwein, S.P., (2002) J. Am. Chem. Soc, 124, p. 5958. , For the total synthesis of laulimalide, see: cAhmed, A., Hoegenauer, E.K., Enev, V.S., Hanbauer, M., Kaehlig, H., Ohler, E., Mulzer, J., (2003) J. Org. Chem, 68, p. 3026Pinnatoxin, A., Ishiwata, A., Sakamoto, S., Noda, T., Hirama, M., (1999) Synlett, p. 692Rodrigues, J.A.R., Siqueira-Filho, E.P., de Mancilha, M., Moran, P.J.S., (2003) Synth. Commun, 33, p. 331Durand, J., Teuma, E., Gómez, M., (2007) C. R. Chim, 10, p. 152Lee, S., (2006) Chem. Commun, p. 1049Sheldon, R.A., (2005) Green Chem, 7, p. 267Davies, J.H., (2004) Chem. Lett, 33, p. 1033Song, C.E., (2004) Chem. Commun, p. 1033Milagre, C.D.F., Milagre, H.M.S., Santos, L.S., Lopes, M.L.A., Moran, P.J.S., Eberlin, M.N., Rodrigues, J.A.R., (2007) J. Mass Spectrom, 42, p. 1287Parvulescu, V.I., Hardacre, C., (2007) Chem. Rev, 107, p. 2615Welton, T., (1999) Chem. Rev, 99, p. 2071Wasserscheid, P., Keim, W., (2000) Angew. Chem. Int. Ed, 39, p. 3773Wilkes, J.S., (2002) Green Chem, 4, p. 73Gu, D.-G., Ji, S.-J., Jiang, Z.-Q., Zhou, M.-F., Loh, T.-P., (2005) Synlett, p. 959Harjani, J.R., Nara, S.J., Salunkhe, M.M., (2002) Tetrahedron Lett, 43, p. 1127Akaiyama, T., Suzuki, A., Fuchibe, K., (2005) Synlett, p. 1024Ranu, B.C., Banerjee, S., Das, A., (2006) Tetrahedron Lett, 47, p. 881Ranu, B.C., Banerjee, S., (2005) Org. Lett, 7, p. 3049Ranu, B.C., Jana, R., (2006) Eur. J. Org. Chem, p. 3767Ranu, B.C., Banerjee, S., Jana, R., (2007) Tetrahedron, 63, p. 776Xu, J.-M., Qian, C., Liu, B.-K., Wu, Q., Lin, X.-F., (2007) Tetrahedron, 63, p. 986Paul, A., Samanta, A., (2007) J. Phys. Chem. B, 111, p. 1957Ranu, B.C., Banerjee, S., (2005) Org. Lett, 7, p. 3049Meciarová, M., Toma, S., Kotrusz, P., (2006) Org. Biomol. Chem, 4, p. 1420Carmichael, A.J., Earle, M.J., Holbrey, J.D., McCormac, P.B., Seddon, K.R., (1999) Org. Lett, 1, p. 997Wang, R., Xiao, J., Twamley, B., Shreeve, J.M., (2007) Org. Biomol. Chem, 5, p. 671Yadav, J.S., Reddy, B.V.S., Gayathri, K.U., Prasad, A.R., (2003) New J. Chem, 27, p. 1684Hajipour, A.R., Rafiee, F., Ruoho, A.E., (2007) Synlett, p. 1118Akike, J., Yamamoto, Y., Togo, H., (2007) Synlett, p. 2168Lancaster, N.L., Llopis-Mestre, V., (2003) Chem. Commun, p. 2812Mehnert, C.P., Dispenziere, N.C., Cook, R.A., (2002) Chem. Commun, p. 1610Chiappe, C., Piccioli, P., Pieraccini, D., (2006) Green Chem, 8, p. 277Santos, L.S., Neto, B.A.D., Consorti, C.S., Pavam, C.H., Almeida, W.P., Coelho, F., Dupont, J., Eberlin, M.N., (2006) J. Phys. Org. Chem, 19, p. 731Yang, X.-F., Wang, M., Varma, R.S., Li, C.-J., (2003) Org. Lett, 5, p. 657Zhao, G., Jiang, T., Gao, H., Han, B., Huang, J., Sun, D., (2004) Green Chem, 6, p. 75Eckstein, M., Filho, M.V., Liese, A., Kragl, U., (2004) Chem. Commun, p. 1084Lou, W., Zong, M., Smith, T.J., (2006) Green Chem, 8, p. 147Gamba, M., Lapis, A.A.M., Dupont, J., (2008) Adv. Synth. Catal, 350, p. 160Zhang, C.Z., (2006) Adv. Catal, 49, p. 153Jain, N., Kumar, A., Chauban, S., Chauban, S.M.S., (2005) Tetahedron, 61, p. 1015Cassol, C.C., Eberling, G., Ferrera, B., Dupont, J., (2006) Adv. Synth. Catal, 324, p. 243Dupont, J., (2004) J. Braz. Chem. Soc, 15, p. 341Rosa, J.N., Afonso, C.A.M., Santos, A.G., (2001) Tetrahedron, 57, p. 4189Kumar, A., Pawar, S.S., (2003) J. Mol. Catal. A: Chem, 208, p. 33Marsh, K.N., Boxall, J.A., Lichtenthaler, R., (2004) Fluid Phase Equilibria, 219, p. 93Jiang, Y.-Y., Wang, G.-N., Zhou, Z., Wu, Y.-T., Geng, J., Zhang, Z.-B., (2008) Chem. Commun, p. 505Pihko, P.M., Erkkila, A., (2006) J. Org. Chem, 71, p. 2538Spectroscopic Data for Ethyl 3-Methylene-2-oxo-4-phenylbutanoate (1) 1H NMR (300 MHz, CDCl3, δ, 1.36 (t, 3 H, J, 9 Hz, 3.65 (s, 2 H, 4.35 (q, 2 H, J, 9 Hz, 5.98 (s, 1 H, 6.23 (s, 1 H, 7.25 (m, 5 H, 13C NMR (75.5 MHz, CDCl3, δ, 14.0, 35.7, 62.2, 126.5, 128.6, 129.2, 133.1, 137.6, 144.4, 163.9, 188.1. MS: m/z, 218 (5, M, 189 (4, 145 (43, 117 (100, 115 (76, 91 (40, 65 (18, 51 (19, Spectroscopic Data for Ethyl 2-Methylene-3-oxo-3-phenylpropionate(2) 1H NMR (300 MHz, CDCl3, δ, 1.10 (t, 3 H, J, 7.1 Hz, 4.19 (q, 2 H, J, 7.2 Hz, 6.2 (s, 1 H, 6.65 (s, 1 H, 7.44 (d, 2 H, J, 7.2 Hz, 7.52 (t, 1 H, J, 7.3 Hz, 7.84 (d, 2 H, J, 7.2 Hz, 13C NMR (75.5 MHz, CDCl3, δ, 14.0, 61.5, 128.5, 129.4, 131.3, 133.5, 136.3, 141.5, 164.0, 193.0. MS: m/z, 204 11, MYamauchi, M., Katayama, S., Watanabe, T., (1982) Synthesis, p. 935Hon, Y.-S., Hsu, T.-R., Chen, C.-Y., Lin, Y.-H., Chang, F.-J., Hsieh, C.-H., Szu, P.-H., (2003) Tetrahedron, 59, p. 1509Chatani, N., Kamitani, A., Oshita, M., Fukumoto, Y., Murai, S., (2001) J. Am. Chem. Soc, 123, p. 1268

Tephrochronology and the extended intimate (integration of ice-core, marine and terrestrial records) event stratigraphy 8–128 ka b2k

The comparison of palaeoclimate records on their own independent timescales is central to the work of the INTIMATE (INTegrating Ice core, MArine and TErrestrial records) network. For the North Atlantic region, an event stratigraphy has been established from the high-precision Greenland ice-core records and the integrated GICC05 chronology. This stratotype provides a palaeoclimate signal to which the timing and nature of palaeoenvironmental change recorded in marine and terrestrial archives can be compared. To facilitate this wider comparison, without assuming synchroneity of climatic change/proxy response, INTIMATE has also focussed on the development of tools to achieve this. In particular the use of time-parallel marker horizons e.g. tephra layers (volcanic ash). Coupled with the recent temporal extension of the Greenland stratotype, as part of this special issue, we present an updated INTIMATE event stratigraphy highlighting key tephra horizons used for correlation across Europe and the North Atlantic. We discuss the advantages of such an approach, and the key challenges for the further integration of terrestrial palaeoenvironmental records with those from ice cores and the marine realm