Band 54, Heft 3

The deprotonation of N-diphenylmethylene-glycine esters, obtained from glycine ester hydrochlorides and benzophenone imine, and reaction of the resulting carbanions with iodomethyl triorganostannanes gives the 3-triorganostannyl-N-diphenylmethylene-alanine esters Me 2 RSnCH 2 CH(N=CPh 2 )COOR′ (1a - e; R = Me, t Bu; R′ = Me, Et, t Bu, Bz). These title compounds are transformed into their tin monochlorides MeR(Cl)SnCH 2 CH(N=CPh 2 )COOR′ (2a - e) by a redistribution reaction with Me 2 SnCl 2 . IR and NMR data and the crystal structure of Me 2 (Cl)SnCH 2 CH(N=CPh 2 )COOEt (2b) reveal for 2a - e an intramolecular coordination of the ester C = 0 group at the tin atom. Mild two-phase hydrolysis of 1a - e with 1N HCl gives the 3-triorganostannyl-alanine ester hydrochlorides Me 2 RSnCH 2 CH(NH 2 )COOR′ · HCl (3a - e). The transformation of 3a - e into the corresponding alanine esters Me 2 RSnCH 2 CH(NH 2 )COOR′ (4a - e) could be realized with NH 3 in chloroform. 4a - e are of limited thermal stability.

The reaction of the N-(diphenylmethylene) Schiff base from glycyl-L-prolyl-L-alanine methyl ester 1 with tetrachloropalladate in the presence of sodium acetate affords the orthopalladated bicyclic C ,N ,O chelate 2. Complex 2 was characterized by X-ray diffraction. Remarkably, the unit cell contains two independent molecules, the cis isomer 2a and the trans isomer 2b (referring to the peptide bond). 2 reacts with PPh 3 by substitution of the carbonyl oxygen atom to give the C,N chelate 3.

The halogenobismuthates Q 3 Bi 2 X 9 (Q = EtMe 2 PhN; X = Cl, Br, I) were prepared by reaction of BiX 3 with EtMe 2 PhNX in ethanol. Single crystal structure determinations yielded: [EtMe 2 PhN] 3 [Bi 2 Cl 9 ], S.G. P2 1 2 1 2 1 , Nr. 19, a = 952.5(3), b = 1184.1(4), c = 3726.4(9 pm, Z = 2;[EtMe 2 PhN] 3 [Bi 2 Br 9 ] S.G .P2 1 /c , No. 14, a= 1839.4(4),b= 1329.5(3), c = 1817.3(6)pm, β = 92.68(3)°, Z = 4, [EtMe 2 PhN] 3 [Bi 2 l 9 ], ], S.G . P2 1 /c, No. 14, a = 1915.3(2), b = 1379.0(3), c = 1890.9(5) pm, β = 92.48(1)°, Z = 4. The thermal behaviour was investigated with the aid of DSC measurements and temperature dependent X-ray powder diffraction. All compounds undergo a transition into a high temperature modification which could be obtained in case of [EtMe 2 PhN] 3 [Bi 2 Br 9-x I x ] in form of single crystals: S.G . P2 1 /c, Nr. 14, a = 1002.7(5), b = 1278.7 (8), c = 3584.3(5) pm, β = 90.12(2)°, Z = 4. Surprisingly in this compound the iodine atoms are not statistically distributed over all possible bromine positions, but occupy only one position. Lattice parameters of the other high temperature modifications and enthalpies of transition of the compounds are given. In addition a second iodobismuthate was isolated:[EtMe 2 PhN] 4 [Bi 6 l 22 ], S.G . P1̄, Nr. 2 , with lattice parameters of a = 1343.4(3), b = 1554.3(3), c = 2262.5(6) pm, a = 100.89(3)°, β = 96.63(1)°, 7 = 98.94(2)° and Z = 2.

2,4,6-Tri-tert-butylphenyltrifluorosilane (1) reacts with lithium amides to give the aminofluorosilanes (2 - 7); RSiF 2 NHR′ (R = 2,4,6-Me 3 CC 6 H 2 ; R′ = H (2), CMe 3 (3), SiMe 2 CMe 3 (4)), (R-SiF 2 ) 2 NH (5), RSiF(NHR′) 2 . R′ = CMe 3 (6), C 6 H 5 (7). The reaction of 5 with BuLi in THF leads to the formation of the monomeric lithium derivative 8, R-SiF 2 Li ⊕ (THF) 3 -N ⊖ -SiF 2 R. The polymeric lithium derivative 9 [R-SiF 2 -N ⊖ -SiRF 2 Li ⊕ (THF) 2 ] n is obtained by recrystallisation of 8 in THF. In 8 and 9 lithium is only coordinated to fluorine and THF. Hydrolysis of 8 or 9 lead to the 1,3-disiloxane 10, (RSiF 2 ) 2 O . 10 shows linearity at the oxygen and short Si-O bond lengths.

The syntheses and structural characterizations of complexes of two 14-membered macrocyclic trans-N 4 dibenzo ligands, 5,7,8,9,14,16,17,18-octahydrodibenzo[e,1]-[1,4,8,11-tetraazacyclotetradecine- 6,15-dimethyl (L 3 ) resp. -6,15-diacetamide (L 4 ), are presented. The crystal structures of five compounds have been determined by single crystal X-ray diffraction. The free ligand L 3 has a saddle-shaped structure with intramolecular hydrogen bonds. This conformation of the ligand exists also in the Zn(II) complex in which the metal ion is five-coordinated with the metal center outside the cavity. The coordination polyhedron is intermediate between a trigonal bipyramid and a square pyramid. In cis-[Ni(L 3 )(NCS) 2 ] the ligand is folded along an N ⋯ N axis. The nickel ion in this complex shows an approximate octahedral geometry. For Ni(II) and Cu(II) complexes of ligand L the overall geometry is also distorted octahedral. The folding of the ligand causes a cis-N 4 O 2 coordination.

Reactions of 2,2′-dipyridylamine (dpyam) with cadmium halides yield crystals of [Cd(dpyam)(H 2 O )Cl 2 ] (1), [Cd(dpyam)Br 2 ] (2), and [Cd(dpyam)I 2 ] (3). With CuCl 2 and KCN a complex [Cu(dpyam )CN] · H 2 O (4) is obtained. Depending on the size of the halide ions the coordination changes from octahedral in 1 to trigonal bipyramidal in 2 and tetrahedral in 3. The coordination in 4 is trigonal. Due to the geometric strain imposed by the ligand all coordination polyhedra show significant distortions. 1 and 2 form dimers by halide bridges. With the exception of 3 all compounds form “supramolecular” structures via hydrogen bonds, e.g. chains or networks.

The reaction of CuCl with [CP 2 MoH 2 ] yields the complex [Cu(Cp 2 MoH 2 ) 2 Cl]. An X-ray structure analysis shows that the coordination of the copper(I) ion by two [CP 2 MoH 2 ] ligands and the chloride ion is pseudo-trigonal planar. The hydride ligands were located by using difference Fourier methods. A manifold of reactions took place when an aqueous solution of CUSO 4 was treated with a solution of [Cp 2 MoH 2 ] in dichloromethane in a 1:2 molar ratio. The X-ray structure analysis established a polymeric structure of the complex [Cu(Cp 2 MoH 2 ) 2 Cu(Cp 2 MoH 2 )SO 4 ] n with two different copper centers.

Re(1,2-diimine)(CO) 3 Cl complexes with the aliphatic bidentate ligands diiminosuccinodinitrile (DISN), benzilbisanile (BEAN), bisacetylbisanile (BABA), and benzildiimine (BEDIM) are reported. The compounds show Re(I) to π*(diimine) metal-to-ligand charge transfer (MLCT) absorptions in the visible spectral region. The energy of these MLCT-transitions decreases in the series BABA > BEDIM > BEAN > DISN, depending on the π* acceptor properties of the coordinated diimine ligands. The maxima of these CT bands undergo a solvent-dependent shift (negative solvatochromism), which indicates a partial charge redistribution in the excited state. The compounds are not photoluminescent at room temperature and 77 K.

The crystal structure of a second room-temperature polymorph of the complex [Au 2 (μ-bis-η 3 -B 6 H 6 )(PPh 3 ) 2 ] is presented and compared with the previously reported phase. The change of the solvent which is layered on a solution of [Au 2 (μ-bis-η 3 -B 6 H 6 )(PPh 3 ) 2 ] in CH 2 CI 2 from petroleum ether to n-pentane leads to a second form with fundamental differences in the crystal structure. Instead of the octahedrally shaped crystals, space group Pa3̄, the crystals in the present determination are orthorhombic needles crystallizing in space group Pccn with a remarkable increased calculated density from 1.326 to 1.855 Mg/m 3 .

By electrochemical oxidation of (n-Bu 4 N)[B 6 H 6 (CH 3 )] in the presence of nitrite ions and of the base DBU in dichloromethane solution cis- and trans-[B 6 H 4 (CH 3 )(NO 2 )] 2- , fac- [B 6 H 3 (CH 3 )(NO 2 ) 2 ] 2- and mer-[B 6 H 3 (CH 3 )(NO 2 ) c 2 ] 2- are formed. X-ray diffraction analyses have been performed on single crystals of cis-(Ph 4 As) 2 [B 6 H 4 (CH 3 O)(NO 2 )] (1) (monoclinic, space group P2 1 /a, a = 20.063(2), b = 10.858(1), c =21.384(2) Å, β = 105.818(9)°, Z = 4), fac-(Ph 4 As) 2 [B 6 H 3 (CH 3 )(NO 2 ) 2 ] ·CH 3 CN (2) (triclinic, space group P1̄, a = 10.333(3), b = 10.695(3), c = 22.833(6) Å, α = 93.91(3), β = 96.79(3), γ = 104.56(2)°, Z = 2), and mer-(Ph 4 P) 2 [B 6 H 3 (CH 3 )(NO 2 ) c 2 ] (3) (triclinic, space group P1̄, a - 10.100(1), b = 10.402(3), c = 22.923(3) Å, α = 96.328(18), β = 89.928(12), γ = 107.963(16)°, Z = 2). The 11 B NMR spectra and the vibrational spectra of the methylnitro compounds are discussed and compared with those of the monomethyl- and mononitro-closo-hexaborates.

The crystal structures of cis-(n-Bu 4 N) 2 [ReCl 4 (NCSe)(SeCN)] (monoclinic, space group P2 1 /n a = 10.794(3), b = 11.687(3), c = 35.716(4) Å, β = 96.97(1)°, Z = 4) and trans- (CH 2 Py 2 )[ReCl 4 (NCSe)(SeCN)] (monoclinic, space group P2 1 /c, a = 8.348(2), b = 7.518(1), c - 31.295(7) Å, ß = 97.12(2)°, Z = 4) have been determined by single crystal X-ray diffraction analysis. Based on the molecular parameters of the X-ray determinations the low temperature (10 K) IR and Raman spectra of the (n-Bu 4 N) salts have been assigned by normal coordinate analysis. The valence force constants are f d (ReN) = 1.68 and f d (ReSe) =1.15 mdyn/Å.

The 2-halo-2,3-dihydro-1H-1,3,2-diazaboroles (1a′: R = tBu, X = Br; 1b: R = 2,6-Me 2 C 6 H 3; X = I) were converted into the 2-amino-2,3-dihydro-1H-1,3,2- diazaboroles (2a: R = tBu; 2b: 2,6-Me 2 C 6 H 3 ) by treatment with dry gaseous ammonia. Similarly reaction of 1a′ with 2,6-dimethylaniline or tBuNH 2 afforded the corresponding derivates (3; R 1 = 2,6-Me 2 C 6 H 3 ; 4; R 1 = tBu). The treatment of 1a′ with the ethylene diamine adduct of lithium acetylide led to the formation of (5). Lithiation of 2 a and subsequent silylation gave 6 (R 1 = SiMe 3 ), which was transformed to the diborolylamine (7) upon exposure to 1a′. Borolylketimine (8 ) and borolylcarbodiimide (9) resulted from 1a′ and Ph 2 C=NSiMe 3 or Me 3 SiN=C=NSiMe 3 , respectively. All the new compounds were characterized by elemental analyses as well as spectroscopic data (IR, 1 H, 11 B, 13 C NMR, MS). Heterocycle 5 was also subjected to an X-ray diffraction analysis.

Tetramethylammonium cyanide crystallizes in the tetragonal space group P4/nmm, Z = 2, with cell dimensions a = 773.6(1), c = 546.8(1) pm. The cyanide ion is disordered in the plane perpendicular to the c-axis indicating a rotation. The room temperature phase undergoes a thermal phase transition at -59.9°C probably caused by an order-disorder transition of the cyanide ion.

The formation of hydrogen bonds to acetonitrile molecules lends stability to the hitherto unknown hydrogenoxonium hexachloroantimonate H 3 O + SbCl 6 - . The structure of H 3 O + SbCl 6 - · 2 CH 3 CN was determined on a single crystal. It crystallises in the orthorhombic space group Pmn2( 1) (Nr. 31) with Z = 2, a = 1 12,7( 1 ),b = 988,8( 1) and c = 1036,5( 1) pm.

The photolysis of Cr(CO) 6 and Ph 3 PAuN 3 (1:2) in thf yields the unstable cluster cation [(Ph 3 PAu) 5 Cr(CO) 4 ] + that slowly decomposes to form the new homometallic gold cluster [Au(AuNCO)(AuPPh 3 ) 8 ]Cl. The cluster compound crystallizes in form of red needles in the tetragonal space group I4 with a = 2214.1(3), c = 1408.9(2) pm, and Z = 2. The inner skeleton of the cluster with the symmetry C 4 consists of a centered square antiprism of nine Au atoms with the square faces of the antiprism being bridged by the AuNCO group, and a Cl - anion, respectively. The shortest Au-Au distances exist between the central and the 8+1 peripheral Au atoms ranging between 263.5( 1) and 270.6(3) pm, the four Au-Cl distances are 280(1) pm.

α-Amino acid esters can be added to a carbonyl ligand of [CpFe(CO) 3 ] + CF 3 SO 3 - to give the carbamoyl complexes Cp(OC) 2 Fe-C(O)NHCHRCO 2 R′ (R = H, Me, CHMe 2 , CH 2 Ph; R′ = Et, Me). This type of reaction may be useful for the marking of peptides at the amino end. The crystal structure of Cp(OC) 2 Fe-C(O)NHCH 2 CO 2 Et was determined by X-ray diffraction.

Primary and secondary trimethylsilyl and tetrahydropyranyl ethers are converted to their carbonyl compounds efficiently using alumina-supported iodobenzene diacetate.

Die Trifluoracetylierungs-Reaktionen verschiedener N-Methylderivate des Tryptamins sowie von N- und O-Methylderivaten des Serotonins mit den Derivatisierungsreagentien: Trifluoracetanhydrid, N-Methylbistrifluoracetamid und Trifluoracetylimidazol wurde analytisch mittels Glas-Kapillar-GC untersucht und die Strukturen der trifluoracetylierten Reaktionsprodukte durch GC-MS-Kombination ermittelt. Fünf dieser Trifluoracetylderivate wurden außerdem präparativ dargestellt und durch MS, IR, 1 H, 13 C und 19 F NMR-Spektren charakterisiert. Im Gegensatz zu Literaturangaben lassen sich die physiologisch interessanten Indolethylamine mit einer tertiärer Dimethylaminoseitenkette (z.B. DMT und Bufotenin) nicht unter den gleichen Reaktionsbedingungen wie bei den anderen Methylderivaten trifluoracetylieren, da die tertiäre Aminogruppierung eine Trifluoracetylierungsreaktion eingeht. Das entsprechende nichtflüchtige N-trifluoracetylierte Produkt wurde von uns präparativ isoliert und spektroskopisch eindeutig charakterisiert.

A new isomer of peradione (2) named as isoperadione (1) has been isolated along with peradione (2) and perovskone (3) from the hexane soluble part of Salvia bucharica. The structures of 1 - 3 were elucidated with the aid of modern spectroscopic techniques.

In connection with the synthesis and epoxidation of campholenic and fencholenic derivatives some trimethylammonium iodides (2 and 4) similar to muscarin were prepared. They may be of interest for the investigation of the cholinergic receptor. The stereochemistry of the epoxytrimethylammonium iodide 4a was determined by NMR and X-ray analysis.

The 1,1′diazacobaltocene pyr 2 Co (3) is obtained from the reaction of 2,5-di-tert-butyl-3-trimethylsilylpyrrole (pyrH, 2) and CoCl 2 . The X-ray structure is reported.