Alkenes from amines

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)... 

Formation of amines from alkenes, carbon monoxide, water, and a nitrogen base was discovered by Reppe who used [Fe(CO)5] to catalyze the process to form amines in low yields 125 199... 

Table 3. Optically Active Secondary Amines From Alkenes via Alkylboronic Esters 1 and Alkyldichlorobo-ranes 2...

Preparation of Tertiary Amines from Alkenes and Secondary Amines. A useful preparation of tertiary amines from alkenes can be achieved when a secondary ozonide is treated with a secondary amine (eq 50) 7 The reaction is quite versatile and provides tertiary amines when the reaction is carried out at reflux after addition of the amine. When the reaction medium was kept at room temperature, isolation of the enamine was observed, making this a clean, four-step, one-pot preparation of morpholino enatnines and tertiary amines for use in s)uithesis. Overall, the reaction performed best with morpholine some problems were encountered with methylenecyclohexane and piperidine, as it seems the enamine intermediate is difficult to form in such a hindered system. 

From an economical and environmental point of view, one pot synthesis of amines from alkenes is a superior pathway over conventional multistep pathways. Hydroaminomethylation is an attractive tool for the synthesis of amines and has been used in the pharmaceutical and chanical industries. Blum developed a heterogeneous system based on [Rh(cod)Cl]2 immobilized within a sol-gel matrix as a highly efficient, regioselective, and recyclable catalyst for hydroaminomethylation reaction of vinylarenes with aniline derivatives (anilines or nitrobenzenes) under mild conditions. 

For molecules similar to safrole or allylbenzene we take the work done on any terminal alkene such as 1-heptene, 1 octene. Another term to look for is olefin which is a term for a doublebond containing species. What we then look for are articles about these olefins where the functional groups we are looking for are formed. Articles with terminology like methyl ketones from (P2P), ketones from , amines from etc. Or when we want to see about new ways to aminate a ketone (make final product from P2P) we look for any article about ketones where amines are formed. Sound like science fiction to you Well, how do you think we came up with half the recipes in this book It works ... 

The preparation of an alkene 3 from an amine 1 by application of a /3-elimination reaction is an important method in organic chemistry. A common procedure is the Hofmann elimination where the amine is first converted into a quaternary ammonium salt by exhaustive methylation. Another route for the conversion of amines to alkenes is offered by the Cope elimination. 

The Hofmann elimination is useful synthetically for preparing alkenes since it gives the least substituted alkene. The reaction involves thermal elimination of a tertiary amine from a quaternary ammonium hydroxide these are often formed by alkylation of a primary amine with methyl iodide followed by reaction with silver oxide. The mechanism of the elimination is shown in Scheme 1.13 in this synthesis of 1-methyl-1-... 

Entries 5 to 7 are examples of oxidation of boranes to the carbonyl level. In Entry 5, chromic acid was used to obtain a ketone. Entry 6 shows 5 mol % tetrapropylam-monium perruthenate with Af-methylmorpholine-lV-oxide as the stoichiometric oxidant converting the borane directly to a ketone. Aldehydes were obtained from terminal alkenes using this reagent combination. Pyridinium chlorochromate (Entry 7) can also be used to obtain aldehydes. Entries 8 and 9 illustrate methods for amination of alkenes via boranes. Entries 10 and 11 illustrate the preparation of halides. 

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