Beim Erhitzen der optisch aktiven Germancarbonsäure (I) bildet sich unter Abspaltung von Kohlenmonoxid der optisch aktive Ester (II).
The stereochemistry of the conversion of (−)-R′3GeCO2H → (−)-R′3GeO2CGeR′3, where R′3Ge Et(1-C10H7)PhGe, is discussed.
AbstractAusgehend von dem German (I) (X = H) wird das optisch aktive (R)‐Äthyl‐ (1‐naphthyl)‐phenylgermyllithium (I) (X = Li) dargestellt, das mit Kohlendioxid (III) in die Carbonsäure (I) (X = COOH) übergeführt wird,.die bei Einwirkung von (II) an der Germanium‐Kohlenstoff‐Bindung unter Rückbildung von (I) (X = Li) gespalten und mit Wasser (IV) wieder in das German (I) (X = H) zurückgeführt werden kann.
AbstractDie Umsetzung von optisch aktivem Äthyl‐(1‐naphthyl)‐phenylgermyllithium (I) mit den Alkylhalogeniden (IIa) erfolgt überwiegend unter Erhalt der Kon= figuration am Gerrnanium, im Fall der Alkylhalogenide (IIb) tritt überwiegend Inversion ein.
The preparation of a range of derivatives from the compound (R)(+)-Et(1-C10H7)PhGeH has led to the establishment of the stereochemistries of some nucleophilic substitutions at the germanium atom. For the reactions studied in both silicon and germanium systems, the stereochemistries are identical to those previously established for the Me(1-C10H7)PhSiX compounds.
The interaction of optically active ethyl(1-naphthyl)phenylgermyllithium, R′3-Ge*Li, with alkyl halides, RX, to give optically active R′3Ge*R compounds, occurs with predominant retention of configuration at germanium in the case of MeBr, i-PrCl, i-PrBr, n-BuCl, n-BuBr, t-BuCl, t-BuBr, CH2CHCH2Cl, CH2CHCH2Br and PhCH2Cl, but with predominant inversion in the case of MeI, i-PrI, CH2CHCH2I, PhCH2I, and PhCH2Br. It is suggested that the retention reactions involve direct coupling between R′3Ge*Li and RX, in a four-centre process, while the inversion reactions involve halogen—lithium exchange, to give R′3GeX and RLi, also in a four-centre retentive process, followed by coupling between R′3GeX and RLi in an invertive process.
Chemischer InformationsdienstVolume 3, Issue 40 Preparative Inorganic Chemistry ChemInform Abstract: ORGANO-GERMANIUMVERBINDUNGEN 10. MITT. DIE STEREOCHEMIE DER SUBSTITUTION AM GERMANIUMATOM BEI EINIGEN RK. MIT NUCLEOPHILEN AGENTIEN C. EABORN, C. EABORNSearch for more papers by this authorR. E. E. HILL, R. E. E. HILLSearch for more papers by this authorP. SIMPSON, P. SIMPSONSearch for more papers by this author C. EABORN, C. EABORNSearch for more papers by this authorR. E. E. HILL, R. E. E. HILLSearch for more papers by this authorP. SIMPSON, P. SIMPSONSearch for more papers by this author First published: October 3, 1972 https://doi.org/10.1002/chin.197240376Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onEmailFacebookTwitterLinkedInRedditWechat No abstract is available for this article. References C. EABORN, R. E. E. HILL, P. SIMPSON, ORGANO-GERMANIUMVERBINDUNGEN 10. MITT. DIE STEREOCHEMIE DER SUBSTITUTION AM GERMANIUMATOM BEI EINIGEN RK. MIT NUCLEOPHILEN AGENTIEN, J. Organomet. Chem., 1972, 37, 251. DOI: 10.1016/S0022-328X(00)96022-4; 10.1016/S0022-328X(00)96022-4 CASWeb of Science®Google Scholar Volume3, Issue40October 3, 1972 ReferencesRelatedInformation
NITROGENASE, which contains iron, molybdenum and thiol groups, operates in an aqueous environment. Many attempts have been made to produce chemical models for nitrogenase based on the above knowledge and recently Schrauzer and co-workers have described dinitrogen-reducing systems of this type1,2 but they use high pressures of dinitrogen (135 atm) and obtain only 3 to 5 μmol. of ammonia from mmol quantities of reagents2 (see Table 1, example 1).
C. Eaborn, R. E. E. Hill and P. Simpson, Chem. Commun. (London), 1968, 1077 DOI: 10.1039/C19680001077