Organometallic Chemistry in Supercritical Water: Metalloorganic Products of the CpCo-Catalyzed Cyclotrimerization of Acetylenes.

Cyclorimetrization of t-butylacetylene or phenylacetylene with CpCo(CO)2 as catalyst in supercritical water yields the isomeric 1.3.5-tris-substituted- (1: R= Ph. 1a: R=bu') and 1.2.4-tris-substituted benzene derivatives (2: R= Ph. 2a: R=bu'). The identification of the organometallic products obtained under these conditions is described. The formation of all possible isomers of the corresponding CpCo (bis-substituted-cyclobutadiene) (3, 4). CpCo(bis-substituted-CpCobaltacyclopentadiene) (5. 6. 7) and CpCo(bis-substituted-cyclopentadienone) 98, 9, 10) via GC-MS is reported. Two of three isomers of CpCo(bis-substituted-cyclopentadienone) (8. 9 (R = Ph), 8a. 9a (R = bu')) were separated and characterized in substance. The structures of 8. 9. 8a and 9a were elucidated by single crystal X-ray diffraction. 8 crystallizes in the orthorhombic space group P2-1, 2-1, 2-1 (No.19) with a=840.5(1), b=1105.9(2), c=1767.2(3) pm. V=1642.8(1)x10-6 pm3, Z=4, D-calc-=1.441 g cm-3. R1=0.0501 (I>3delta), wR1=0.0529 (I>3delta). 9 crystallizes in the orthorhombic space group Pna2-1 (No. 33) with a =1086.7(1). b=4726.0(1), c=1668.5(1) pm. V=8427.3(1)x10-6 pm3, Z=20, D-calc=1.404 g cm-3, R1=0.0705 (I>2 delta). Rw=0.1321 (all data on F2w). 8a crystallizes in the monoclinic space group P2-1/c (No.14) with a=1441.6(3), b=1241.3(1), c=3672.6(6) pm. Beta=92.39(2)*, V=6566(2)x10-6 pm3. Z=16. D-calc=1.280 g cm-3. R1=0.082 (I>2 delta). Rw=0.144 (all data on F2). 9a crystallizes in the monoclinic space group P2-1/c (No. 14) with a=669.3(1), b=1335.7(1), c=1843.1(1) pm. Beta=94.78(1)*. V=1641.9(1)x10-6 pm3. Z=4.Dcale=1.28 g cm-3, R1=0.0622 (I>2 delta. Rw= 0.1185 (all data on F2).

BORWIECK H.;  WALTER O.;  DINJUS E.;  REBIZANT Jean; 

1999-01-18

JRC17719