Bicyclobutanes Research Articles

Cyclobutane-bicyclobutane system. 8. Nucleophilic "addition-elimination" displacements on activated bicyclobutanes

Dans le methanol CN − reagit avec le chloro-3 bicyclobutanecarbonitrile-1 pour donner une substitution sur le chlore et une addition de HCN au niveau de la liaison centrale. Le derive bromo-3 subit seulement la substitution. Dans le DMSO, avec un exces de chloro-3 bicyclobutanecarbonitrile-1, le produit principal est le bicyclobutanedicarbonitrile-1,3. En presence d'un exces de CN − on obtient le cyclobutanetricarbonitrile-1,1,3

Synthese d'aza-1 bicyclobutanes tri ou tetrasubstitues a substituant vinylique

Aza-1 bicyclobutanes 1 are readily prepared by reaction of azirines with gem-chloro(alkyl)allyllithium reagents.

Synthese photochimique d'aza-1 bicyclobutanes

Aza-1 bicyclobutanes 2 are readily obtained by photolysis of carbamates 1 . 1 are easily synthetised from 3 .

Bicyclobutanes from cyclopropylidene insertion reactions and photolytic closure of a diene

Isopropyliden-cyclohexan (I) reagiert mit dem aus Bromoform erhaltenen Dibromcarben (II) zum Addukt (III), das mit Methyllithium zunachst zum Carben (IV) reagiert.

Synthesis of bicyclobutanes: exclusive insertion of a cyclopropylidene into primary rather than tertiary carbon-hydrogen bonds.

Das Dibromcyclopropan (I) erhalt man aus 2,3,4-Trimethyl-penten-(2) und Bromoform/Kalium-tert-butylat in Pentan, es liefert bei der Behandlung mit Methyllithium bei -40°C, 10°C oder 36°C die Bicyclobutane (II)-(IV).

Selective insertion of cyclopropylidenes in the formation of bicyclobutanes

Selective insertion of cyclopropylidenes in the formation of bicyclobutanes

Synthesis and polymerization of bridgehead-substituted bicyclobutanes

Synthesis and polymerization of bridgehead-substituted bicyclobutanes

New model for the bonding in bicyclobutanes

New model for the bonding in bicyclobutanes

Electronic Structures and Reactivities of Aliphatic Polycyclo Compounds. I. Fused Three-membered-ring Compounds

Abstract The electronic structures of bicyclo(1.1.0)butane, tricyclo(3.1.0.0)hexane, tricyclo(2.1.0.0)pentane, tricyclo(1.1.0.0)butane, prismane, and spiro(2.2)pentane are studied by the extended Huckel method. The calculated total energies of bicyclo(1.1.0) butanes with various dihedral angles, θ, and bridgehead C–C–H angles, α, show that the most stable configuration of bicyclo-butane is at α=135° and θ=115–120°. It is made clear that the s-nature of the carbon atoms of the C–Haxial and C–Hequatorial depends greatly on the dihedral angle of the two cyclopropane rings. The double-bond character between the bridgehead carbon atoms in the bicyclobutane and its homologues is pointed out. The stabilities of the C–C bonds of prismane are shown to be largely dependent on the angle between the C–H bond and the four-membered-ring plane. The electronic structures of some configurations of spiropentane with different dihedral angles are discussed. The physico-chemical properties of these compounds are briefly investigated.