NaBH4 In Methanol Research Articles

Phosphordonor-substituierte Formylmangan-Komplexe /Phosphorous Donor Substituted Formyl Manganese Complexes

Abstract Phosphonomanganese complexes (CH3O)2(O)PMn(CO)3[P(OCH3)3]2 (1b), (CH3O)2(O)PMn(CO)2[P(OCH3)3]3 (1c) are obtained via demethylation of the corresponding cationic substituted carbonylmanganese compounds with KHB(secBu)3. The reaction of NaBH4 in methanol with cationic phosphorus donor substituted carbonyl manganese compounds leads to formyl complexes (OC)3L2MnCHO (L = P(OCH3)3 (3a), L = P(OEt)3 (3c), L = P(OiPr)3 (3d), L = PPh3 (3e)) and (OC)2[P(OCH3)3]3MnCHO (3b). 3d decomposes thermally to give an (OC)3[P(OiPr)3]2 MnH and an (OC)2[P(OiPr)3]3MnH complex. The latter has been characterized by an X-ray structure determination.

Carbonyl and hydridocarbonyl complexes of ruthenium (II) and osmium (II) with tertiary arsines

Ruthenium halides (Cl and Br) react with monotertiary arsines-Ph2RAs (R=Me, Et, Prn) in methoxyethanol, in the presence of aq. formaldehyde to give monocarbonyl complexes of ruthenium(II) of the type RuX2(CO) (Ph2RAs)3. Carbonylation of an ethanolic solution containing ruthenium trichloride and the arsine at room temperature yieldtrans dicarbonyl compounds of the formula RuCl2(CO)2 (Ph2RAs)2. The osmium monocarbonyls OsX2(CO) (Ph2RAs)3 (X=Cl, Br; R=Me, Et) react with NaBH4 in methanol to yield complexes of the composition OsHX(CO) (Ph2RAs)3. The ruthenium analogues RuHCl(CO) (Ph2RAs)3 have also been made. Structures have been assigned to all these compounds on the basis of IR and NMR spectral results.

ChemInform Abstract: SYNTHESIS OF 3,6‐DIETHOXYCARBONYL‐3,6‐EPIDITHIA‐1,4‐DIMETHYL‐2,5‐PIPERAZINEDIONE AND RELATED COMPOUNDS, FORMATION OF C‐S BOND BY THE REACTION OF CARBANION AND SULFUR MONOCHLORIDE

AbstractDas aus dem Aminomalonsäureester (I) durch Erhitzen auf 160‐180°C unter Stickstoff erhaltene Pyridazindion (II) gibt in Dioxan beim Behandeln mit Natriumhydrid und anschließend mit frisch destilliertem Dischwefeldichlorid das Gemisch aus den Epithia‐Verbindungen (IIIa) (17 %), (IIIb) (9 %) und geringen Mengen von (IIIc) und (IIId).

Synthesis of 3,6-diethoxycarbonyl-3,6-epidithia-1,4-dimethyl-2,5-piperazinedione and related compounds. Formation of C-S bond by the reaction of carbanion and sulfur monochloride.

Reaction of 3, 6-diethoxycarbonyl-1, 4-dimethyl-2, 5-piperazinedione (15), prepared by heating of diethyl methylaminomalonate (14), with NaH in dioxane and followed treatment with S2Cl2 gave 3, 6-epidithio- and 3, 6-epitetrathio-3, 6-diethoxycarbonyl-1, 4-dimethyl-2, 5-piperazinediones (16b and 16d), which have the skeletone (1) observed in fungal metabolites such as sporidesmin. The reduction of 16 with NaBH4 in methanol gave the dethio derivative (15) in good yield. The reaction of 16d with triphenylphosphine in tetrahydrofurane gave 16c and 16b. The reaction of diethyl malonate derivatives (23a, b, and c) with NaH and S2Cl2 in dioxane gave the corresponding disulfides or trisulfides (24a, b, and c). Some reactions of proline anhydride (5) and sarcosine anhydride (7) with S2Cl2 or sulfur were examined.