Printed in the Republic of Korea (η 5 -Cyclopentadienyl)-µ-(η 5 -,2,3,4,5-Pentamethyl-,3-diborole)Cobalt šq w * w ww yw (2007. 5. 7 ) : Keywords: Study of Ring-Expansion of (η 5 -Cyclopentadienyl)-µ-(η 5 -,2,3,4,5- Pentamethyl-,3-diborole)Cobalt Complex Jae-Kook Uhm* Department of Chemistry, College of Natural Science, Keimyung University, Daegu, 704-70 Korea (Received May 7, 2007),2,3,4,5-Pentamethyl-,3-Diborole gp e šq Ring Expansion-,2,3,4,5-Pentamethyl-,3-Diborole Cobalt Sandwich complexes,4-dibora-2-cyclohexene ww e w. Boron sww 5y(five membered ring) xl yw,3-diborole () Binger w w.,2,3,4,5-pentamethyl-,3-diborole (2) ww š, e w. 2-4 µ-(η 5 -,2,3,4,5-Pentamethyl-,3-diborole)-cobalt šq 3b w ww w š w. (3) () (4) (2) (3) (5) e w. c,5 p η 5 -Cp- (5) 387
388 ƒ ww» (3), (4) mw ky ù, (5) š y ù yw.,6,7,8 (5) ww ü.»» Schlenk» w. w Ar ƒ ( W.A. Hammond t) gš, w» w BTS-( BASF t) w. 9 x Aldrich, Merck t Ar ƒ potassium, sodium, š CaH 2 benzophenone ƒw z w w w. NMR y Bruker AC-200, Bruker WX-360, B- NMR Jeol FX-90Q»», IR Bruker, mass-spectra Varian MATCH 7 ƒƒ w dw. ƒ Gallen Kamp. M.P. apparatus»» dw. Aldrich, Strem, š Merck p t w w. w jm v w, silica gel 60( Merck t) 60 o C w k z Arƒ w.,2,3,4-tetramethyl-,4-dibora-2-cyclohexene(2) ww w yw w, NMR yw. 70%. H-NMR(δ, C 6D 6): 0.85(s, 6H, B-CH 3),.45(s, 4H),.94(s, 6H, =C-CH 3) 3 C-NMR(δ, C 6D 6): 63.4(br, C=C), 25.8(br, CH 2), 8.2(CCH 3), 2.0(br, B-CH 3) B -NMR(δ, C 6D 6): 73.8 ppm,2,3,4,5-pentamethyl-,3-diborole() yw w 0 šp (pressure tube) yw, 2 š w, 73%š NMR yw. H -NMR(δ, C 6D 6):.85(s, 6H, =C-CH 3),.48(q, H, -CHCH 3),.20[d, 3H, -CHCH 3, 3 J(HH)=6.8Hz], 0.70(s, 6H, B-CH 3) 3 C-NMR(δ, C 6D 6): 72.5(s, br, C=C), 4.2[d, br, CHCH 3, J(CH)=04Hz], 4.0[q, CCH 3, J(CH)=24.3Hz], 0.0[qd, CHCH 3, J(CH)=25.Hz, 2 J(CH)=6Hz], 3.6 [q, br, BCH 3, J(CH)=5Hz], 2.0(br, BCH 3) B -NMR(δ, C 6D 6): 70.4 ppm (η 5 -Cyclopentadienyl)-µ-(,2,3,4,5-pentamethyl-,3- diborole) cobalt 4 yw Jonas [(C 5H 5)Co(C 2H 4) 2] yww š, 3 g e, 3 4, ƒƒ 25% 23%. 3; H-NMR(δ, C 6D 6): 4.0(s, 5H),.62(s, 6H, =C-CH 3),.0(s, 6H, B-CH 3), 0.88[d, 3H, -CHCH 3, J(HH)=3.8Hz], -8.50[q, H, J(HH)=3.8Hz]. B-NMR(δ, C 6D 6): 26 ppm. MS(EI): m/z 258 (M +, 00), 242 [(M-CH 4) +, 52], 230 [(M-C 2H 4) +, 20], 227[(M-C 2H 7) +, 22], 26[(M-BC 2H 7) +, 38], 202[(M-C 3H 0) +, 0], 33[(2-H) +,.4], 24[(CpCo) +, 4; H-NMR(δ, C 6D 6): 4.0(s, 5H),.50(s, 6H, =C-CH 3),.2(s, 6H, -CH 3), 0.92(s, 3H, -CCH 3), -.32(s, Co-H) B-NMR(δ, C 6D 6): 20 ppm. MS(EI): m/z 258 (M +, 00), 242 [(M-CH 4) +, 52], 230 [(M-C 2H 4) +, 20], 227[(M-C 2H 7) +, 22], 26[(M-BC 2H 7) +, 38], 202[(M-C 3H 0) +, 0], 33[(2-H) +,.4], 24[(CpCo) +, (η 5 -Cyclopentadienyl)-µ-(,2,3,4,5,6-hexamethyl-,4- dibora-2-cyclohexene)cobalt (5) 00 ml Schlenk tube yw, 750 mg(5.22 mmol) Jonas 980 mg(5.44 mmol) š l 30 ml ƒwš reflux e w z 60 o C ƒw 2 g. TLC ywš silica gel jm
(η 5 -Cyclopentadienyl)-µ-(η 5 -,2,3,4,5-Pentamethyl-,3-diborole)Cobalt šq w 389 v w w., 3 š,, 3i ƒƒ. w z kù w, 5 y. 3; H-NMR(δ, C 6D 6): 4.0(s, 5H),.62(s, 6H, =C-CH 3),.0(s, 6H, B-CH 3), 0.88[d, 3H, -CHCH 3, J(HH)= 3.8Hz], -8.50[q, H, J(HH)=3.8Hz]. 3 C-NMR(δ, C 6D 6): 82.4(5C), 96.4(C=C), 5.8(=C- CH 3), 8.8(CH-CH 3), 3.6(CH-CH 3), 0.4(B-CH 3). B-NMR(δ, C 6D 6): 25.9 ppm. MS(EI): m/z 258 (M +, 00), 242 [(M-CH 4) +, 52], 230[(M-C 2H 4) +, 20], 227[(M-C 2H 7) +, 22], 26[(M- BC 2H 7) +, 38], 202[(M-C 3H 0) +, 0], 33[(2-H) +,.4], 24[(CpCo) +, 36] 65(Cp +, 4.0) 59(Co +, 6.6) 3i; H-NMR(δ, C 6D 6): 4.0(s, 5H),.50(s, 6H, =C-CH 3),.2(s, 6H, B-CH 3), 0.32(s, 3H, -CCH 3), -0.9(s, H) B-NMR(δ, C 6D 6): 9.8 ppm. MS(EI): m/z 258(M +, 00), 242[(M-CH 4) +, 52], 230 [(M-C 2H 4) +, 20], 227[(M-C 2H 7) +, 22], 26[(M-BC 2H 7) +, 38], 202[(M-C 3H 0) +, 0], 33[(2-H) +,.4], 24[(CpCo) +, 5; H-NMR(δ, C 6D 6): 0.88(s, B-Me).50(s, 4Me) 3.96 (s, Cp). 3 C-NMR(δ, C 6D 6): 82.0(5C), 96.8(C=C), 5.6(C- CH 3), 9.98(B-CH 3). B-NMR(C 6D 6)δ: 24.4 ppm. MS(EI) m/e 286(M +, 00)[27(M-Me) +, 45.2], 245[(M- BMe 2) +, 8.8] 60[(M-CpCo) +, 5.8] 24[(CpCo) +, 35.6] 65(Cp +, 0.4) 59(Co +, 6.8) 57[(Me 3BH) +, 84.8] 4[(Me 2B) +. 73.6]. š µ-(,2,3,4,5-pentamethyl-,3-diborole) cobalt, 3, (6) ùkü. 4 60 C 2 o j x e w, 5ƒ dw., Jonas j 60 o C, Jonas ww ethylene w ƒ w gp ww. diborole ƒ g p ww 3 E agostic k2 ƒ ethylene ƒ ƒ. ƒ ethylene 7e,3 ethyl diborole 4 k ƒ w ww 3E. methylene w š ƒ t w k ww 5i,(η 5 -Cyclopentadienyl)-µ-(,2,3,4,5,6-hexamethyl-,4- dibora-2-cyclohexene)cobalt k. yw 6 ƒ(valence electron) ƒ, 4 ƒwù w. yw 5 w w kw, 5ƒ dw. 3b,5 e Scheme ùkü. Jonas (η 5 -Cyclopentadienyl)-µ-(,2,3,4,5,6-hexamethyl-,4- dibora-2,5-cyclohexadiene)cobalt (5), 2 Jonas [CpCo(C 2H 4) 2]» x (η 5 -Cyclopentadienyl)- Scheme. Expected Mechanism of Complex 5 by the Ring- Expansion.
390 60 o C ww. ethylene ƒ ƒ ww w w y ƒ. diborole šq w,4-dibora-2,5-cyclohexadiene ëš ƒ. 2, 3 w, 3iƒ, 3i w. j w ethylene ƒ, y, 3 4. (6) 6 ƒ 6 ƒ 3i ƒ w. w ü yw. 4 (6) 2 w sww 5yyw,,3-diborole,2,3,4,5-pentamethyl-,3-diborole Jonas 60 C 2 j o, 5 (η 5 -Cyclopentadienyl)-µ-(,2,3,4,5,6-hexamethyl-,4-dibora-2,5-cyclohexadiene)cobaltƒ. Jonas ww ethylene ƒ ƒ wƒ, š q w 6ƒx šƒ ƒw. ù (2005. 8~2006. 8) Erlangen-Nuernberg w yw Zenneck, Ulrich w, w w w. x. a) Uhm, J. k.; Hu, D.; Zenneck, U.; Pritzkow, H.; Siebert, W., J. Kor. Chem. Soc., 990, 34, 490. b) Woerner, K.-F.; Uhm, J. k.; Pritzkow, H.; Siebert, W., Chem. Ber., 990, 23, 239. c) Uhm, J. k., Ph. D. Dissertation, Universitaet Heidelberg, 987. 2. a) Binger, P., Tetrahedron Lett., 966, 24, 2675. b) Binger, P., Angew. Chem., 968, 80, 288, Angew. Chem. Int. Ed. Engl, 968, 7, 286. 3. a) Roemich, H., Ph.D. Dissertation, Universitaet Heidelberg, 987. b) Stumpf, K., Ph.D. Dissertation, Universitaet Heidelberg, 985. 4. Uhm, J. k., J. Kor. Chem. Soc., 2005, 49, 329. 5. a) Uhm, J. k., J. Kor. Chem. Soc., 998, 42, 340. b) Uhm, J. k.; An, H. W., J. Kor. Chem. Soc., 997, 4, 586. 6. a) Siebert, W., Angew. Chem. 985, 97, 924, Angew. Chem. Int. Ed. Engl. 985, 24, 943. b) Timms, P. L., J. Chem. Soc. Chem. Comm. 969, 033. c) Herberich, G. E.; Mengesbach, J.; Koelle, G.; Frank, A., Angew. Chem. 976, 88, 450. 7. a) Herberich, G. E.; Heßner, B.; Beswetherik, S.; Howard, J. A. K.; Woodward, P., J. Organomet. Chem. 980, 92, 42. b) Herberich, G. E.; Heßner, B.; Huttner, G.; Zsolnai, L., Angew. Chem. 98, 93, 47. c) Herberich, G. E.; Heßner, B.; J. Organomet. chem. 987, 6, C36. d) Herberich, G. E.; Mengesbach, J.; Koelle, G.; Oschmann, W., Angew. Chem. 977, 89, 43. 8. a) Siebert, W., Pure. Appl. Chem. 987, 59, 947. b) Koehler, F. H.; Zenneck, U.; Edwin, J.; Siebert, W., J. Organomet. Chem., 98, 208, 37. c) Siebert, W.; Ender, U.; Herter, W., Z. Naturforsch. 985, 40B, 326. d) Wadepohl, H.; Siebert, W., Z. Naturforsch. 984, 39B, 50. e) Ender, U., Ph.D. Dissertation, Universitaet Heidelberg, 984. 9. Schuetze, M., Angew. Chem. 958, 70, 693. 0. Uhm, J. k.; Roemich, H.; Wadepohl, H.; Siebert, W., Z. Naturforsch. 988, 43B, 306.. Jonas, K.; Krueger, C., Angew. Chem. 980, 92, 53, Int. Ed. Engl. 990, 9, 520. 2. a) Brookhart, M.; Green, M. L. H., J. Organomet. Chem. 983, 250, 395. b) Brookhart, M.; Lamanna, W.; Humphrey, M. B., J. Am. Chem. Soc. 982, 04, 27. c) Lamanna, W.; Brookhart, M., J. Am. Chem. Soc. 98, 03, 989. 3. Edwin, J.; Boehm, M. C.; Chester, N.; Hoffman, D. M.; Hoffman, R.; Pritzkow, H.; Siebert, W.; Stumpf, K.;
(η 5 -Cyclopentadienyl)-µ-(η 5 -,2,3,4,5-Pentamethyl-,3-diborole)Cobalt šq w 39 Wadepohl, H., Organometallics, 983, 2, 666. 4. Sidwick, N. V., Trans, Faraday, Soc. 923, 9, 469. 5. Uhm, J. k., unpublished personal result. 6. a) Koester, R., Angew. Chem. 983, 75, 079. b) Rossi, F. M.; Mccusker, P. A.; Hennion, G. F., J. Org. Chem. 967, 32, 450.