Carbene in räumlich begrenzten Systemen I. 1,3‐C‐H‐Insertionsreaktion von Adamantyliden im β‐Cyclodextrin‐Hohlraum

Abstract

Die ersten intra‐ und intermolekularen Carbeninsertionen in einem räumlich begrenzten molekularen Reaktionsgefäß konnten bei der Photolyse des festen Einschlußkomplexes 1·β‐Cyclodextrin(CD) nachgewiesen werden. NMR‐spektroskopische und/oder massenspektrometrische Untersuchungen belegen die Bildung von Produkten wie 2·β‐CD und 3·β‐CD.

Supramolecular Photochirogenesis with Carbenes Entrapped in Cyclodextrins

“…The advantages of TRIMEB over 7-Cy are a better solubility of the complexes (7-Cy complexes tend to be poorly soluble) and a larger size of the crystals obtained which facilitates structure analysis and identification of the products resulting from photolysis. In contrast, if 7-Cy is used as reaction vessel, the alkyl carbene to a significant amount may also insert into the O-H bonds of the host, [18] a process that also explains the low recovery of products after irradiation of 1b@7-Cy. But since TRIMEB does not possess functional groups or bonds which are susceptible to react easily with a relatively nucleophilic alkyl carbene, [7] 1a only can rearrange intramolecularly, affording endo-tricyclo[3.3.0.0 2,8 ]octan-3-ol (7a) [19] and bicyclo[3.3.0]oct-5-en-3-ol (6a) [20] in a ratio depending on the host molecule used.…”

Carbene rearrangements. 43. Carbenes in Constrained Systems. 2. First Carbene Reactions within Zeolites: Solid-State Photolysis of Adamantane-2-spiro-3'-diazirine

“…Adamantane-2-spiro-3'-diazirine (1) was prepared from adamantanone (5) according to Isaev et a/.4a on the basis of the general method of Schmitz and Ohme.26 All reagents were obtained commercially and used without further purification. Where dry, water-free solvents were necessary, those were distilled from lithium aluminum hydride under a N2 or Ar atmosphere.…”

“…Here, 13C NMR spectroscopy was used to determine the product ratios of 2,4-dehydroadamantane (4), adaman tanone (5), and 2-adamantanol (6). Signal intensities of the product mixture obtained were compared to those of a standard solution of 2,4-dehydroadamantane (4), adaman tanone (5), and 2-adamantanol (6). All spectra were standardized and run under the same conditions.…”

“…30% within /3-cyclodextrin. 5 The reactivity of adamantylidene (3) had been altered dramatically by its inclusion into /3-cyclodextrin. However, adamantanone azine (7), which is formed in an intermolecular reaction, still dominates the photolysis reaction of 1 (ca.…”