Konformationsanalyse und Diastereomerenzuordnung an 1,3-Aza- und 1,3-Oxaphospholanen mittels paramagnetischer Verschiebung

The geometric factor G [G = (3 cos² θ ?1) r^?3] of selected protons relative to a centre of co-ordination [Eu(dpm)₃] is determined using Dreiding models of different conformers of 1,3-aza- and 1,3-oxaphospholanes. The centre of co-ordination is supposed to be joined to the oxygen of the carbonyl group or to the nitrogen and oxygen in the hetero-ring, respectively. The graphs of the geometric factors against the paramagnetic shifts of the relevant protons are straight lines only for the preferred conformers on the basis of a correct centre of co-ordination. As a measure for the paramagnetic shift of a proton the slope of the graph of chemical shift against the concentration of Eu(dpm)₃ (in mol %) is chosen. By variation of the relative configuration at C-5 in the models and calculation of the geometric factor, it is possible to determine the different diastereomers, which are distinguished by the relative position of the substituent at phosphorus and C-5.     

Heterotricyclodecane XVI. 2-Oxa-7-aza-isotwistane und 2-Oxa-7-aza-twistane

The synthesis of several derivatives of 2-oxa-7-aza-isotwistane ( 20–29 and 35 ) and 2-oxa-7-twistane ( 30–34 ) is described starting from cis,cis-cycloocta-1, 5-diene ( 1 ). The bicyclic acetoxy-olefin 10 was used as a key intermediate. The 10^N(7)-isotwistane 22 was treated under reaction conditions suitable for molecular rearrangements involving an oxonium ion g , by neighbouring group participation, leading to 2-oxa-7-aza-twistanes.     

Heterotricyclodecane XI,Sulfoxide und Sulfone von 2-Oxa-7-thia-isotwistan und 2-Oxa-7-thia-twistan sowie Derivaten

The synthesis of sulfoxides and sulfones of 2-oxa-7-thia-isotwistane ( 24 ) and 2-oxa-7-thia-twistane ( 35 ) as well as of several of their derivatives is described. endo-2-Hydroxy-9-thiabicyclo[3.3.1]non-6-ene ( 5 ) was used as starting material. During the course of the reactions special attention was given to intramolecular hydroxy-mercuration and jododemercuration reactions, spectroscopic features, molecular rearrangements and stereospecificity of oxidations of sulfides to sulfoxides.     

Heterotricyclodecane X. 2-Oxa-7-thia-isotwistan und 2-Oxa-7-thia-twistan sowie Derivate

The synthesis of 2-oxa-7-thia-isotwistane ( 11 ) and 2-oxa-7-thia-twistane ( 22 ) as well as of several of their derivatives is described starting from endo-2-hydroxy-9-thiabi cyclo[3.3.1]non-6-ene ( 4 ). The 10^O(2)-isotwistane bromide 13 , iodide 14 and tosylate 30 as well as the 10^S(7)-isotwistane iodide 15 , tosylate 20 , and the 10^S(7)-twistane tosylate 21 were treated under reaction conditions suitable for molecular rearrangements involving the epi-sulfonium ion i and the oxonium ion g . respectively, by neighbouring group participation.     

Pteridine. Teil LXXIX. Synthese,Reaktionen und Photochemie heterocyclischer N,-Alkylthioamide

Synthesis, Reactions, and Photochemistry of Heterocyclic N-Alkylthioamides Various heterocyclic N-alkylthioamides of the pteridine ( 2, 7 ) and pyridine series ( 13 ) have been synthesized and investigated regarding their photooxidation. The compounds are very photolabil under aerobic conditions and are converted into the corresponding amides ( 1, 6 and 12 , resp.) on irradiation.     

Phosphirenes and Azaphosphetines: IX. 1-Aza-2-phospha-1,3-dienes, 1,2-Azaphosphetines,and 1-Aza-2-phosphacyclohexa-2,4-dienes in Reactions with P-Bromoimino-N-(tri-tert-butylphenyl)phosphine with 1-Dialkylamino-1-alkynes

The reaction of P-bromoimino-N-(tri-tert-butylphenyl)phosphine with 1-dialkylamino-1-alkynes primarily forms 1-aza-2-phosphabitadienes. The latter are unstable and can further rearrange into 1,2-azaphos-phetines or take up one more aminoacetylene molecule to give 1-aza-2-phospha-2,4-cyclohexadienes.     

Heterotricyclodecane XIV. 2-Oxa-6-aza-adamantan und Derivate

The synthesis of 2-oxa-6-aza-adamantane ( 21 ) and several of its derivatives ( 13–20 , 22 , 23 , 25–34 , 37 , and 38 ) was achieved starting from the 9-azabicyclo[3.3.1]nona-2,6- dienes 2 , and 3 , and 9-oxabicyclo[3.3.1]nona-2,6-diene ( 1 ).     

Nickel-katalysierte Mischoligomerisation von 2-Aza-1,3-butadienen mit 1,3-Butadien. Vorläufige Mitteilung

Nickel-catalysed Reaction of 2-Aza-1, 3-butadienes with 1, 3-Butadiene The nickel-catalysed reaction of butadiene with 2-azabutadienes yields a mixture of 1 aza-1,5,9-cyclododecatrienes, N-alkylidene-divinylcyclohexylamines and open chained 2:1 adducts.     

Heterotricyclodecane XIX. Umlagerungen von 4,8-disubstituierten 2,6-Dioxa- und 2-Oxa-6-aza-adamantanen zu 4,10-disubstituierten 2,7-Dioxa- und 2-Oxa-7-aza-isotwistanen sowie -twistanen

Rearrangements of 4,8-disubstituted 2,6-dioxa- and 2-oxa-6-aza-adamantanes to 4,10-disubstituted 2,7-dioxa- and 2-oxa-7-aza-isotwistanes as well as -twistanes. Substitutions and rearrangements involving neighboring group participation starting from 4,8-diiodo-2,6-dioxa- and 4,8-diiodo-2-oxa-6-aza-adamantanes ( 5 and 6, 12 and 48 , resp.) were studied, yielding 4,8-disubstituted 2,6-dioxa- and 2-oxa-6-aza-adamantanes ( 7, 9, 39, 42 and 13, 15, 50, 52 , resp.), 4,10-disubstituted 2,7-dioxa- and 2-oxa-7-aza-isotwistanes ( 8, 10, 41, 43 and 14, 16, 51, 53 , resp.) and corresponding-twistanes ( 11 and 17 , resp.).     

IR-Spektroskopische Untersuchungen an 1,3-Dioxa- und 1,3-Diaza-2-boracyclopentanderivaten

Zusammenfassung Die IR-Spektren von mehreren Dioxa- und Diazaboracyclopentanderivaten wurden zusammen mit jenen von C-deuterierten Verbindungen untersucht. Besonderer Wert wurde auf die Klärung von Kopplungen zwischen BN-, BO- und CH₃-Schwingungen im Bereich zwischen 1550 bis 1300 cm^–1 gelegt.

---

IR-spectra of several dioxa- and diaza-boracyclopentanes have been studied together with those of some C-deuterated analogues. Special attention has been given to coupling effects of BN-, BO-, and CH₃-modes in the 1550–1300 cm^–1 region.

---

---

Mit 3 Abbildungen     

Acyl- und Alkylidenphosphane. XXVIII. Synthese und Struktur von 1,3-Dibenzyl- und 1,3-Diethyl-2,4-bis(phenylimino)-1,3-diphosphetan

Acyl- and Alkylidenephosphines. XXVIII. Synthesis and Structure of 1,3-Dibenzyl- and 1,3-Diethyl-2,4-bis(phenylimino)-1,3-diphosphetane Catalyzed by small amounts of solid sodium hydroxide, the adducts 1a and 1b formed from benzyl- or ethylbis(trimethylsilyl)phosphine and phenylisocyanate, react at +20°C slowly to give hexamethldisiloxane and oligomeric [(phenylimino)methylidene]phosphines. In different solvents the benzyl compound was found to exist only as a mixture of [N,N′-(E)/(Z)]-isomeric 2,4-bis-(phenylimino)-1,3-diphosphetanes 2a with their alkyl groups at the phosphorus atoms in trans position, whereas in case of the ethyl derivative 2b a second pair of [N,N′-(E)/(Z)]-isomeric dimers with their substituents in cis position and two trimeric forms ( 3b and 4b ) could be detected in cyclopentane. [N,N′-(E)]-1r,3t-dibenzyl- ( 2a ) and [N,N′-(E)]-1r,3t-diethyl-2,4-bis(phenylimino)-1,3-diphosphetane 2b isolated from 1,2-dimethoxyethane or cyclopentane, crystallize in the monoclinic space group P2₁/c or P2₁/n, resp., with following dimensions of the unit cell determined at temperatures of measurement of +20 ± 3°C/?130 ± 3°C: a = 2145.4(1)/569.3(1); b = 568.1(2)/719.1(2); c = 1960.2(2)/2042.6(4) pm; β 99.43(1)°/95.03(2)°; Z = (2+2) and 2, resp. X-ray structure determinations (R_w = 0.034/0.041) show both molecules to be centrosymmetric. Characteristic rounded bond lengths (pm) and angles (°) are: endocyclic P? C 185/184; C? P? C 82/81; P? C? P 98/99; exocyclic P? C 186/184; C?N l27/127; C?N? C 121/11.     

1,3-Dipolare Cycloaddition aromatischer Nitril-ylide und Nitril-oxide an Dicyan und Diazocyanide

1,3 Dipolar Cycloaddition of Aromatic Nitrile Ylides and Nitrile Oxides with Cyanogen and Diazocyanides Nitril ylides 2 generated from the imidoyl chlorides 1 react with cyanogen and aryldiazocyanides to 2,5(4)-dia-ryl-1H-imidazole-4(5)-carbonitriles 3a , b or 5(4)-(arylazo)-2,4(5)-diaryl-1H-imidazoles 4a and 2,3,5-triaryl-2,3-dihydro-1H-1,2,4-triazole-1-carbonitriles 5a – f , respectively (Scheme 1). Reactions of benzonitrile oxides 7 with these dipolarophiles lead to 3,3′-diaryl-5,5′-bi[1,2,4]oxadiazoles 8a – c or 3-aryl-5-(arylazo)-1,2,4-oxadiazoles 9a – j (Scheme 2).     

1,3-Cycloaddition von alkinen an hetero-1,3-diene 1-aminopyrrole aus 1,2-diazabuta-1,3-dienen und 1-diethylaminopropin

1-Aminopyrroles (4) are obtained by reaction of 1,2-diazabuta-1,3-dienes (1) and ynamines (2). This reaction represents one of the very rare examples of 1,3-cycloaddition processes of alkynes and hetero-1,3-dienes.     

Massenspektrometrie heterocyclischer Verbindungen, 2. Mitt.: Das Fragmentierungsverhalten einiger 2-Acylmethylbenzothia-,-selena-und-imid-azole

The effect of the second heteroatom,X, on the fragmentation mode of compounds1–7 is analyzed.     

Bildung siliciumorganischer Verbindungen. 74. Synthese und NMR-Spektren von Si-methylierten und -chlorierten 2,2-Dichloro-1,3-disilapropanen und 2-Methyl-2-chloro-1,3-disilapropanen

Formation of Organosilicon Compounds. 74. Synthesis and NMR-Spectra of Si-methylated and -chlorinated 2,2-Dichloro-1,3-disilapropanes and 2-Methyl-2-chloro-1,3-disilapropanes The compounds me₃Si? CCl₂? Sime_nCl_3?n (n = 1–3; me = CH₃) are synthesized by reaction of me₃Si? CCl₂Li (formed from me₃Si? CCl₂H with n-buLi, bu = butyl) with the appropriate methylchlorosilanes. The compounds Clme₂Si? CCl₂? Sime_nCl_3?n are obtained by analogous reactions of (C₆H₅)me₂Si? CCl₂Li, cleavage of the Si-phenyl group with bromine and conversion of the Si? Br to the Si? Cl group with HCl in PCl₃. The 2-methyl-2-chloro-1,3-disilapropanes are synthesized by lithination of the CCl₂ group of 2,2-dichloro-1,3-disilapropanes, followed by reaction with meI. (Clme₂Si)₂CmeCl is obtained from (C₆H₅me₂Si)₂CCl₂ by reaction with n-buLi to (C₆H₅me₂Si)₂ CClLi, which forms (C₆H₅me₂Si)CClme with meI. Cleavage with bromine to (Brme₂Si)₂CClme and reaction with HCl/PCl₃ leads to the expected compound. The influence of the substitution on the ¹H, ¹³C and ²⁹Si NMR spectra is investigated.