Stereochemical Control in Organic-Synthesis Using Silicon-Containing Compounds

The oxidation of the carbon-silicon bond

Structurally Diverse pi-Cyclopentadienyl Complexes of the Main Group Elements.

Allylsilanes in Organic Synthesis − Recent Developments

An overview of recent transition metal-catalyzed syntheses of pyrroles and carbazoles is presented The focus is on methods which have been applied to the preparation of biologically active naturally occurring pyrrole and carbazole alkaloids For pyrroles, special attention is paid to silver(I)-catalyzed cyclization reactions For carbazoles, iron(0)-mediated and palladium(0/II)-catalyzed cyclization reactions are highlighted and their broad range of applications is discussed

Synthesis of Pyrrole and Carbazole Alkaloids

A Versatile and Efficient Synthesis of Annulated Cyclopentanes by Stereoselective [3 + 2] Cycloaddition of Allylsilanes and Cycloalkenyl Methyl Ketones

The (η4-1-azabuta-1,3-diene)tricarbonyliron complexes 10 are easily prepared in high yield by condensation of the corresponding arylamines 7 with the cinnamaldehydes 8 and subsequent ultrasound-promoted complexation of the resulting 1-azabuta-1,3-dienes 9 with nonacarbonyldiiron. The complexes 10 are shown to represent excellent reagents for the transfer of the tricarbonyliron fragment onto cyclohexa-1,3-diene (1a). The structural characterization for the complexes 10 is achieved by IR, 1H-NMR, and 13C-NMR spectroscopy, as well as X-ray crystallography of 10b, 10c, and 10l. Using variable temperature 13C-NMR spectroscopy the fluxionality of the complexes 10a, 10b, 10c, 10e, and 2 is investigated and the activation barrier for the turnstile rotation of the tricarbonyliron fragment is determined. The transfer reaction and the structural factors influencing the transfer of the tricarbonyliron fragment are extensively investigated.

Synthesis, Molecular Structure, Fluxional Behavior, and Tricarbonyliron Transfer Reactions of (η4‐1‐Azabuta‐1,3‐diene)tricarbonyliron Complexes

The titanium tetrachloride promoted reaction of allylsilanes 1 with 1-acetylcyclohexene is shown to afford the silylbicyclo[4.3.0]nonanes 9 ([3 + 2] cycloaddition products) along with the 1-acetyl-2-allylcyclohexane 4 (Hosomi-Sakurai product). Here we report that systematic variation of the substituents at the silicon atom of 1 allows suppression of the classical Hosomi-Sakurai reaction in favor of the [3 + 2] cycloaddition. Cycloaddition of the allylsilanes 1d, 1i, and 1 k with 1-acetylcycloalkenes 10, containing a 5-, 6-, 7-, 8-, or 12-membered ring, gives rise to the corresponding silylbicyclo[n.3.0]alkanes 11 – 13. The cycloaddition of allyltriisopropylsilane (1 k) and 1-acetyl-2-methylcycloalkenes 15 provides silylbicyclo[n.3.0]alkanes 16 with two contiguous quaternary carbon centers. The stereochemistry of the silylbicyclo[n.3.0]alkanes 11 a - c and 14 is unambiguously determined by X-ray analysis and 13C NMR spectroscopy.

Highly Stereoselective Synthesis of Bicyclo[n.3.0]alkanes by Titanium Tetrachloride Promoted [3 + 2] Cycloaddition of Allylsilanes and 1-Acetylcycloalkenes†

Norbert Foitzik

Papers

A Versatile and Efficient Synthesis of Annulated Cyclopentanes by Stereoselective [3 + 2] Cycloaddition of Allylsilanes and Cycloalkenyl Methyl Ketones

Synthesis, Molecular Structure, Fluxional Behavior, and Tricarbonyliron Transfer Reactions of (η4‐1‐Azabuta‐1,3‐diene)tricarbonyliron Complexes

Highly Stereoselective Synthesis of Bicyclo[n.3.0]alkanes by Titanium Tetrachloride Promoted [3 + 2] Cycloaddition of Allylsilanes and 1-Acetylcycloalkenes†

[3+2] cycloadditions of allylsilanes - 4.

Eine vielseitige und effiziente Synthese anellierter Cyclopentane durch stereoselektive Cycloaddition von Allylsilanen und Cycloalkenylmethylketonen