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Cage Extension to Clusters with Co2Co3MoAs6 Polyhedron Frameworks.

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C5 can be reliably determined from the mass spectra of 10 by
using the base peak (m/z 69 corresponds to a fragment ion
with C5-'H2; m/z 67 corresponds to C5-'H,).1'2. 13] The
deuterium at C2 in 8 is lost as expected; the deuterium on the
aldehyde groups in 9 is not lost and thus rules out additional
redox reactions on the way to 10 or 11. The isomeric diol
(62)-8 is not metabolized.
When the larvae of P. versicolora are treated with the diol
8 and the resulting metabolites are subjected to analysis by
mass spectrometry, the results indicate that two separate
(Scheme 1, B) cyclases might be operating in the defense
glands of this larva. The resulting I-nor['H,]chrysomelidial
10 has two deuterium atoms attached to C5, whereas the
typical main product for this larva, I-nor['H,]plagiodial 1I ,
has lost one of the two hydrogen isotopes from the C4 atom
of the precursor 8. In addition, a 3-nor[2H,]plagiolactone
corresponding to 5 has also only one deuterium atom attached to C5, which shows that it is derived from I-norplagiodial 11. Whether the lack of the methyl group of the
nor precursor causes this kind of product distribution still
needs to be examined. The two deuterium atoms attached to
C5 of I-nor['H,]chrysomelidial 10 rule out the possibility
that l-nor[2H,]plagiodiaI 11 is first formed and that the thermodynamically more stable 10 is produced by isomerization
of 11.
Interestingly, the larvae of P. cochleariae have developed
precisely this pathway (Scheme I , C; see also Fig. 1). After
the injection of 8 exclusively 1-nor[2H,]chrysomelidial 10 is
found in their defense secretion. In 10, one of the two enantiotopic deuterium atoms attached to C4 in the precursor is
missing. The use of chiral (4R,5S)- o r (4S,5R)-3-nor[4,52H,]geraniol of the type 7 ( 297 % ee at C4) as precursor['l
leads to the enantiospecific removal of the C4-Hs hydrogen
atom. Since the loss of a hydrogen atom from the C5 atom
of the iridoid skeleton, regardless of the cyclization mechanism, determines the position of the ring double bond, for P.
cochleariae it must be assumed that plagiodial3 occurs as an
intermediate on the way to chrysomelidial 1. This finding is
in formal accordance with the current theory of an acid-catalyzed cyclization[lO1of 8-oxocitral to 1. It can be supposed
that the direct formation of 10 and 11 from a common intermediate of the cyclization occurs through the loss of a hydrogen atom from C2 and C5, respectively. Regardless of mechanistic aspects, it is, however, clear that in the course of
evolution, at least within the genus Phaedonini (subfamily
Chrysomelinae), two different pathways have been deveioped for synthesis of 1. Further biogenetic studies on iridoidproducing larvae of the Phaedonini should make it possible
to characterize members of this genus chemotaxonomically.
Received: December 17, 1992 [Z5755IE]
German version: Angeii. Chcm. 1993, 105, 904
[l] C. A. Boros, F. R. Stermitz, J Nut. Prod. 1990, 53, 1055.
[2] L.-F. Tietze, Angew. Chcm. 1983, 95. 840; Angew. Chem. h t . Ed. E q l .
1983, 22, 828.
[3] H. Inouye, S. Uesato, f r o g . Chem. Org. Nut. Prod. 1987, 50, 169.
[4] S. R. Jensen, 0. Kirk, B. J. Nielsen, fhytochemistry 1989, 26, 97.
[5] G. W. Dawson, D. C. Griftiths, N. F. Janes, A . Mudd, J. A. Picket. L. J.
Wadhams, C. M. Woodcock, Naiure. 1987, 325, 614.
[6] J. M. Pasteels, M. Rowell-Rahier, J.-C. Braekman, D. Daloze, Biochem.
Syst. Ecol. 1984,12,395; K. Dettner, R. Fettkother, 0.Ansteeg, R. Deml.
C . Liepert, B.Petersen, E. Haslinger. W. Francke, J. Appl. Entomol. 1992,
113, 128; A. Hutz, K. Dettner. J. Chem. Ecol. 1990, 16, 2691.
[7] J. M. Pasteels, J. C. Braekman, D. Daloze, R Ottinger, Tetrahedron, 1982,
38, 1891.
[S] J. Meinwald. G. M. Happ, J. Labows, T. Eisner. Science 1966, 1 5 / , 79
[9] M. Lorenz, W Boland, unpublished results.
[lo] S. Uesato, Y Ogawa, M. Doi, H. Inouye. J Chem. Soc. Chem. Commun.
1987. 1020.
914
Q VCH Verlugsgesellschali mbH, W-6940 Weinheim. 1993
[I 11 F. Bellesia, F. Ghelfi, U. M. Pagnoni, A. Pinetti, Tetrahedron Lett. 1986,
381.
[12] A 1 : 1 mixture of I-norchrysomelidial and I-norepichrysomehdial [zHH,]-10
was obtained by boiling the dialdehyde ['H,]-9 (0.15g, 0.95 mmol) in 60%
HCOOH for 1 h [lo]. Chromatography on SiO, with hexdne/Et,O (3:7
vlv) yielded 63 mg (42%) ['HJlO. MS (Finnigan, Ion Trap ITD 800,
70eV): mi; 157 ( M ' . 1.4%), 139(6), 138(5). 129(14), 128(6), 114(4),
113(4), 112(8). 111(15), 110(11). 109(6), 100(18), 99(13). 98(12), 97(29).
96(35). 95(36), 94(17). 93(12), 92(6), 85(7). 84(9), 83(19). 82(18), 81(18),
80(18), 79(16), 78(1 I). 71(9), 70(29), 69(100). 68(75), 6?(43). 66(28). 65(1 I),
64(8), 59(12). 58111). 57(9), 56(11), SS(11). 54(11). 53(15), 52(14), 46(12).
High-resolution MS; calcd. for C,H,'HH,O,: 157.1151: found. 157.1182.
I131 According to high-resolution mass spectrometry (Finnigan MAT 90). the
base peak for ['HJ-lO (mi: 69) corresponds to a fragment ion of the
structural formula C,H,'H: and contains the C atoms of the ring; with
the exception of a deuterium atom from the aldehyde group (C?) (cf.
Scheme 1) n o deuterium from the side chain is transferred to the ring
during the fragmenation of 10. This was confirmed by using reference
substances of varying degrees and patterns of deuteration 191. A hypothetical fragmentation scheme for irtdodial is discussed in ref. [14].
1141 S. Uesato, Y Ogawa, H . Ihouye, K. Saiki, M. H. Zenk, Etruhid-on Lett.
1986, 27, 2893.
Cage Extension to Clusters with Co,/Co,MoAs,
Polyhedron Frameworks**
By Michaela Detzel, Karl Pfeiffer, Otto J. Scherer,* and
Gotthelf Wolmershauser
Dedicated to Professor Heinrich Noth
on the occasion of his 65th birthday
The synthesis of molecules exclusively constructed from
L,M and naked E, units (E = P, As, Sb, Bi) has developed
into an unusually manifold area of research, particularly in
recent tirnes."l Little is known, however, about the reactivity
of such complexes.[']
The desired extension of Co,/Co,As, cage frameworks to
nona- and decanuclear heteroatom clusters has now been
and 2['] (Cp* = $-C,Me,) to react
achieved by allowing lL2]
with [Mo(CO),(thf)]. The respective products, 3 (violet crystals) and 4 (black crystals), are stable in air for a short period
and dissolve scarcely in n-hexane, better in benzene and
toluene, and easily in dichloromethane. The complexes are
formed in satisfactory (3: 47%) and good (4: 74%) yields,
respectively.
The X-ray structure analysisC3'shows that for 3 the trapezoidal face of the As, ligand in 1 which is still free is capped
by the 12e- fragment [Mo(CO),], which, however, does not
change the total number of the skeletal electron pairs (SEP).
With 11 SEP, 1 belongs to the arachno type (n + 3) and 3 to
the nido type (n + 2) of structure. The framework of the
nonanuclear cluster 3 can be described as a stretched, triply
capped trigonal As,CoMo prism (Fig. l), in which the three
long edges are almost of the same length (As1 . . . As3 3.032,
As4...As6 3.023, Mo-Col 3.030 A; sum of the covalent
radii according to Pauling: As-As = 2.42, Mo-Co =
2.46 A). This leads to parallel triangular faces (dihedral angle 0.6 ") and to six As-As bond lengths, whose average value
is 2.47 A. The framework of the Co,MoAs, polyhedron of 3
[*] Prof. Dr. 0 . J. Scherer, Dipl.-Chem. M. Detzel, Dr. K. Pfeiffer,
['I
[**I
Dr. G. Wolmershiuser"'
Fachbereich Chemie der Universitit
Erwin-Schrodinger-Strasse,D-W-6750 Kaiserslautern (FRG)
Telefax: Int. code + (631)205-3200
X-ray structure analyses
This work was supported by the Fonds der Chemischen lndustrie.
0570-0833/93/0606-0914$ 10.00+.25jO
Angeu. Chem. h i . Ed, Engl. 1993, 32, No. 6
[Mo(CO),(thf)],
-
2 CO
Fig. 2a) Molecular structure of 4 without ligands. Selected distances [A] and
angles ["I: Col-Mo 2.933(3), Col-As1 2.285(4), Col-As2 2.28613). Col-As6
2.400(4). Co2-As2 2.407(4), Co2-As4 2.424(4), Co2-As5 2.31 5(4), Co2-As6
2.434(3). C03-Asl 2.422(4), Co3-As3 2.425(4), C03-As5 2.309(4). C03-AS6
2.447(4), Mo-As1 2.667(3), Mo-As2 2.679(3), Mo-As3 2.714(3), Mo-As4
2.716(3), Asl-As3 2.594(3), As2-As4 2.565(3), As3-As4 2.579(3), As3-As5
2.587(3), AS4-As5 2.585(3), Asl-As6 2.874, As2-As6 2.872, As5-As6 2.831 ;
C02-As5-Co3 110.1(1), CoZ-As6-Co3 101.9(1). AsS-Co2-As6 73.2(1), As5C03-As6 73.0(1), Asl-Col-AsZ 105.7(1), Col-AsZ-As4 115.2(1), Col-Asl-As3
115.0(1). Asl-As3-As4 101.4(1), As2-As4-As3 102.4(1). b) Sphenocorona; the
ideal polyhedron was simulated by refinement of the structural model of 4 with
suitable fixation of the bond lengths.
cca3
2
4
four-membered rings Col, As2, C02, As6, and Col, Asl,
co3, As6 (sum of the angles each 359.9 ") are rhomboidally
distorted, leading to an As.. . As diagonal distance of 2.87
(shown as a dashed line in Fig. 2a). b) In contrast to the
five-membered ring Asl, As2, As3, As4, Col, (sum of the
angles 539.7 '; maximum deviation of the least-squares
plane = 0.05 A) the corresponding ring in sphenocorona is
not planar (maximum deviation of the least-squares
plane = 0.30
c) The rhomboidally distorted, almost planar four-membered ring C02, As5, co3, As6 (sum of the
angles 358.2", fold angle 167.4", As5.. . As6 2.83 A) in 4 is
contrasted by two neighboring three-membered rings (fold
angle 159.9') in the ideal polyhedron (Fig. 2b). The remaining five As-As bonds are almost identical in length (average
2.58 A).
In spite of the Co,MoAs, heteroatom cluster framework
the asphericity["] determined for 4 (23.4%) deviates only
slightly from that of sphenocorona (18.9%['01), a MI, polyhedron framework, which has so far not been found for
transition metal clusters." Compound 4, however, shows a
noteworthy structural parallel to gold clusters of the composition [Au, 1(PR3)7X3].1112' Inside the Au,, framework (cf.
Fig. 2), consisting of ten triangles and three nonplanar quadrangles, is an interstitial gold atom, which obviously makes
a significant contribution to the stability of the peripheral
Au,,
121
In contrast to the complexes 1,'212JZ1and 3, compound 4
shows no dynamic behavior as revealed by 'H NMR studies.I61
A
shows interesting parallels to the Bi; cluster ion 5,L4I both
with regard to the number of skeletal electrons (22, i.e.
n + 2 = 11 SEP) and to the hie ratio ( h = average value of
the three long edges of the prism, e = average value of the six
edges of the triangles), which for 3 is 1.17 and for 5 is 1.15.
In 5 (1 1 SEP) the occupation of the antibonding a'; orbital
(HOMO) is responsible for the elongation of the trigonal
prism;*41in B,H:- (10 SEP) this orbital is the LUMO.'']
+
Fig. 1 . Molecular structure of 3 without ligands. Selected distances [A] and
angles ["I: Col-Mo 3.030(3), Col-As1 2.518(3), Col-As2 2.434(3). Col-As5
2.426(3), Col-As6 2.516(3), C02-Asl 2.364131, C02-As3 2.413(3), Co2-As4
2.412(3), Co2-As6 2.364(3), Mo-As2 2.588(2), Mo-As3 2.813(2), Mo-As4
2.817(3), Mo-As5 2.604(2), Asl-As2 2.481(3), As2-As3 2.509(3), As3-As4
2.433(3). As4-As5 2.509(3), Asl-As6 2.423(3), As5-As6 2.492(3), Asl-As3 3.32,
As4-As6 3.023. As2-As5 3.873; Asl-AsZ-As3 74.8(1), As4-As5-As6 74.4(1),
As2-As3-As4 106.4(1), As3-As4-As5 107.0(1),As2-Asl-As6 107.0(1), Asl-AshAs5 106.9(1): torsion angle As1,2.5.6jAs2,3.4,5 78.6".
A).
Experimental Procedure
'H NMR investigations at different temperaturesL6Ishow
that the singlet for the Cp* ligands of 3 at room temperature
splits into two separate signals for the Cp* Iigands at Col
and C02 only at low temperature. These spectroscopic results indicate a rapid framework rearrangement often observed for nonanuclear clusters.r41
The X-ray structure analysisL3'for the decanuclear heteroatom cluster 4 reveals a Co,MoAs, polyhedron framework (Fig. 2a), which corresponds to a distorted sphenocoronaL71(Fig. 2 b).[91 In comparison with the ideal
polyhedron (Fig. 2 b), the following important deviations
are observed for the framework of 4 (Fig. 2a): a) The planar
Angrw. Chrm. Inr. Ed. E n d . 1993. 32. No. 6
6
3 [4]' To 1 121 (81 mg, 0.094 mmol) [2 (300 mg, 0.29mmol) [2]] was added a
solution of [Mo(CO),(thf)], prepared by irradiation (90 min) (water-cooled
150 W mercury high-pressure lamp) of [Mo(CO),] (240mg. 0.091 mmol) in
freshly distilled T H F (50 mL). After the mixture had been stirred for 20 h at
room temperature the reaction mixture was concentrated, adsorbed on to
AI,O, (ca. 1 g) (basic, 2 % H,O), and dried. In the purification by column
chromatography (column 25 x 2.5 cm, packed with Al,O,/petroleum ether)
with petroleum ethetitoluene (lil), exclusively 3 was eluted as an auberginecolored [4 as a dark brown] fraction. After the solvent had been removed 3
(47 mg, 47%) [260mg, 74%,4] was obtained spectroscopically pure. Recrystallization was achieved by Layering a concentrated solution of 3 [4] in
dichloromethane with n-hexane at room temperature; 3 formed violet. hexagonal crystalline platelets [4 dark brown to black crystal needles].
VCH Vrrlaxsgesellschafi mbH, W-6940 Weinheim,1993
Received: January 21. 1993 (Z5820IEI
German version: Anxew. Chem. 1993, 10.7, 936
0570-0833/93~0606-0915
$ 10.00+.28/0
91 5
[l] Most recent reviews: a ) O . J. Scherer, Angeir. Chem. 1990. 102, 11371155; Angew. Chem. fnf. Ed. Engl. 1990,29, 1104-1122; b) M. Scheer, E.
Herrmann. 2. Chem. 1990,30.41-55; cj T. P. Fehlner. C. E. Housecroft,
R. N. Grimes in Inorgunometaliic Chemisfry (Ed.: T. P. Fehlner), Plenum,
New York, 1992, Chapters 2. 3 , 6.
[2] 0. J. Scherer, K. Pfeiffer, G Heckmann, G. Wolmershiuser, .l
Orgunumei.
Chem. 1992, 425. 141 -149.
[3] a) 3monoclinic. C2/c(no.15); a = 37.654(7). h = 9.459(1), L‘ = 17.016(3) A,
/i
= 105.772(8)”, 2 = 8,3781 independent reflections (Mo,,; 26,,, = 48 ’),
of which 2805 observed with 1 2 2a(/): 316 parameters, R(R,) =
0.062(0.061). b) 4 monoclinic, P2Jn. u = 11.609(2), b =16.948(1),
( = 21.894(4) A, fl = 99.16(1)”, Z = 4,
5187 independent reflections
(Mo,,; 20,,, = 48-), ofwhich 3369 observed with I t 2 4 1 ) : 267 parameters. R(R,j = 0.072(0.077). 4 contains about 1 disordered molecule
CH,CI, per formula unit. One C1 atom occupies two different general
positions (population ratio 0.610.4). c) Enraf-Nonius (CAD-4), T = 298 K,
solution and refinement of the structures with the programs SHELXS-86,
SHELX-76. Further details of the crystal structure investigations may he
obtained from the Fachinforniationszentrum Karlsruhe, Gesellschaft fur
wissenschaftlich-technische Information mbH. D-W-7514 EggensteinLeopoldshafen 2 (FRG) on quoting the depository number CSD-57030,
the names of the authors, and the journal citation.
[4] J. D. Corhett, Chem. Rev 1985, 85, 383-397. and references therein.
[5] M. E. O’Neill, K.Wade, J. Mul. Slruct. 1983, 103, 259-269.
161 ’ H NMR (400 MHz): 3 (C,D,, TMS ext j : 6 (298 K ) =1.28 ( s , 3OH); d
(190 K) =1.30 (s. 15H). 1.10 ( 5 , lSH), T, = 231 K, ACT*= 46 & 1
kJ mol- 4 (C,D,): d (298 K) = 1.63 (s, 30H). 1.91 ( s , 15 H). 1R (CH,CI,,
i.(CO)[cm-’]): 3: 1931 (vs), 1857 (br, s), 4: 1929 (vs), 1862 (br, s).
[7] The sphenocorona (Zalgaller polyhedron no. 86 I S ] ) has C,, symmetry and
consists of 10 vertices (2:4:2:2). 14 faces (12 equilateral triangles, 2
squares), and 22 edges.
[8] V. A. Zaigaller. Seminars in Muthemutrcs, Vol. 2 (Convex Puiyhedru with
Regulur Fares). Consultants Bureau, New York, 1969, pp, 1-92.
[9] Extensive discussion of the coordination number 16 in: D. L. Kepert,
Inorgunir S/ereurhemi.str.v, Springer, Berlin 1982, pp. 188-193.
[lo] L. A. Aslanov, V. T. Markov, Acta Cr.ysfa//ogr.Sect. A 1989,45,661-671.
[ l l ] D. M. P. Mingos, A. S. May in The Chemisfry of’MetalCIusterComplexes
(Eds.: D. F. Shriver, H. D. Kaesz, R. D. Adams), VCH, Weinheim. 1990,
pp. 62 - 70.
[ 1 2 ] P. Bellon, M. Manassero, M. Sansoni, J. Chem. Suc. Daifon Truns. 1972,
3481-3487.
Corrigendum
In the communication “The Seven-Component Reaction”
by A. Domling and I. Ugi (Angew. Chem. Znt. Ed. Engl. 1993,
32, 563 - 564) structural formula 14 is incorrect. The correct
formula is:
$C
tBuN-
14
O.KOMe
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