Alkene analogs

The addition of N-bromosuccinimide (1.1equiv) to a dichlo-romethane solution containing the alkene (1 equiv) and cyana-mide (4 equiv). The solution was maintained at room temperature (3 days) and then washed with water, dried, and concentrated in vacuo. Treatment of the bromocyanamide [intermediate] with 1% palladium on charcoal in methanol (1h) led to reduction of the for-madine. Addition of base to the reaction mixture (50% aqueous KOH, reflux 6h) followed by extraction with ether gave monoamine. (Yield is 48-64% final amine from alkenes analogous to safrole)... 

Anodic oxidations of the Mo(II) bis-cyclopentadienyl alkyne compound Mo(jj -C5H5)2( i -C2Ph2), and of metal-alkene analogs such as Mo(j -C5H5)2(j7 -C2H4) involve a reversible one-electron oxidation at very facile potentials. The v(CC) alkyne stretch in the IR spectrum of 17-electron Mo-alkyne cation (1824 cm ) was shifted by 50cm to a higher wave number to that of its parent, consistent with a decrease in the metal-alkyne interaction in the Mo(III) cation. 

The macromolecules of many polymers include C=C bonds and therefore can be considered as alkene analogs. This gives rise to the idea of applying the carboxidation approach to polymers. It was expected to open up a new way for their chemical modification so as to improve the adhesion and other physicochemical properties. 

Figure 22 Geometry of alkene and alkene analogs (a) planar geometry, angle between CH2 plane and C-C bond =0° (b) trans-bent geometry, angle between ER2 plane and E-E bond > 0°...

Several isomeric forms can be written for group 13 triple bonds, shown in Figure 26. Bending of the C-Ga-Ga angle away from 180° is evidence for the presence of lone pairs, and calculations on a variety of model compounds are consistent with a Ga Ga bond order of 2. The isomeric form with one n bond and one delocahzed lone pair (as in the group 14 alkene analogs) is possibly the best description of this molecule. ... 

This reaction proceeds via transmetallation to generate an organopalladium intermediate which readily adds across the carbon-carbon double bond of the alkene. Rapid cis-palladium hydride / elimination generates the substituted alkene. Analogous reactions - with carbon monoxide are used to synthesize carbonyl compounds ... 

Butadienoate esters undergo AICI3 and EtAlCh catalyzed stereospecific [2 + 2] cycloadditions with a wide variety of alkenes to give alkyl cyclobutylideneacetates in good yield. The stereospecificity and ratios of ( )- and (Z)-isomers suggest a [ 2 + v2a] cycloaddition of the ester-Lewis acid complex to the alkene analogous to the cycloaddition of ketenes with alkenes. Similar results are obtained with methyl 2,3-pentadienoate, methyl 4-methyl-2,3-pentadienoate and methyl 2-methyl-2,3-butadi-... 

Magat first reported the use of r-alkyl halides as Ritter reaction substrates but, in general, these were less satisfactory than the use of the corresponding alcohol or alkene analogs. This process has since come into its own for polycyclic systems, where simple methods of generating bridgehead halides are often available. An early example is Stetter s conversion of 1-bromoadamantane to the acetamide (30), there-... 

As mentioned above, the chemistry of distannenes, >Sn=Sn<, the tin analogs of ethylene, has the longest history among all heavy alkene analogs of the type > E=E < (E, E are heavier group 14 elements). The first stable compound with an Sn=Sn double bond, 1, was reported by Lappert et al. in 1973. Since then, distannenes 6-17 have been synthesized and characterized, and some of their parameters... 

Since the late 1990s, new classes of heavy alkene analogs containing tin, i.e., silastannenes and germastannenes, have been investigated. ... 

Cycloadditions. iV,iV -Di-t-butylthiadiaziridine 5,5-dioxide reacts with activated terminal alkenes in the presence of CuCl and BU3P to give live-membered heterocycles This reaction effectively performs the critical step of vic-diamination of the alkenes. Analogously, cyclic iV-cyanoguanidine 1 also undergoes cycloaddition to alkenes, with PhsP to stabilize CuCl. ... 

Figure 24 Resonance forms arising from cr +7r mixing in trans-bent group 14 alkene analogs...

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