Generation of endo- and/or exo-norbornenecarboxaldehyde as an intermediate to functionalized norbornenes
View Patent ↗Embodiments in accordance with the present invention provide for forming essentially pure diastereomers of 5/6-substituted norbornene-type monomers. Further, embodiments in accordance with the present invention encompass polymerizing such diastereomers to form addition or ROMP polymers where a desired exo-/endo-ratio of the diastereomers is provided to the polymerization, such ratio designed to provide a desired ratio of endo-/exo-structured repeating units for a resulting polymer to have desired physical or chemical properties.
1. A method for forming an essentially pure exo- and/or endo-substituted norbornene monomers, comprising:
forming a diastereomeric mixture of norbornenecarbonitrile (NBCN) via a Diels-Alder reaction;
separating the exo- and endo-diastereomers of such diastereomeric mixture;
first converting an individual NBCN diastereomer to the analogous diastereomeric norbornenecarboxaldehyde (NBCHO); and
second converting an individual NBCHO diastereomer to one of the analogous norbornenecarboxylic acid or alcohol.
2. The method of claim 1 , where the first converting comprises charging a reaction vessel with a metal hydride and an individual NBCN diastereomer to effect a reduction of said NBCN, and subsequently hydrolysing the reaction intermediate.
3. The method of claim 1 , where the second converting comprises charging a reaction vessel with a hydride donor reagent and an individual NBCHO diastereomer to effect a reduction of said NBCHO.
4. The method of claim 1 , where the second converting comprises charging a reaction vessel with an appropriate oxidizing agent and an individual NBCHO diastereomer to effect an oxidation of said NBCHO.
5. The method of claim 2 , where the second converting comprises charging a reaction vessel with an appropriate oxidizing agent and an individual NBCHO diastereomer to effect an oxidation of said NBCHO.
6. The method of claim 2 , where the second converting comprises charging a reaction vessel with an appropriate reducing agent and an individual NBCHO diastereomer to effect a reduction of said NBCHO.
7. The method of claim 2 , where the second converting comprises charging a reaction vessel with a hydride donor reagent and an individual NBCHO diastereomer to effect a reduction of said NBCHO.
8. The method of claim 2 , where the metal hydride comprises lithium aluminum hydride, alkyl aluminum hydrides, alkoxyaluminum hydrides, or dialkylamino lithium hydrides.
9. The method of claim 1 , further comprising
using the analogous norbornenecarboxylic acid or alcohol in a transition metal polymerization.
10. The method of claim 1 , where separating the exo- and endo-diastereomers of the diastereomeric mixture comprises distilling the exo- and endo-diastereomers.
11. The method of claim 1 , where separating the exo- and endo-diastereomers of the diastereomeric mixture comprises fractionally distilling the exo- and endo-diastereomers.
12. The method of claim 1 , where the diastereomeric mixture of NBCN comprises bis-norbornenecarbonitriles.
13. A method for forming at least a 95% diastereomerically pure exo- and/or endo-substituted norbornene monomers, comprising:
forming a diastereomeric mixture of norbornenecarbonitrile (NBCN) via a Diels-Alder reaction separating the exo- and endo-diastereomers of such diastereomeric mixture;
first converting an individual NBCN diastereomer to the analogous diastereomeric norbornenecarboxaldehyde (NBCHO); and
second converting an individual NBCHO diastereomer to one of the analogous norbornenecarboxylic acid or alcohol.
14. The method of claim 13 , where the first converting comprises charging a reaction vessel with a metal hydride and an individual NBCN diastereomer to effect a reduction of said NBCN, and subsequently hydrolysing the reaction intermediate.
15. The method of claim 13 , where the second converting comprises charging a reaction vessel with a hydride donor reagent and an individual NBCHO diastereomer to effect a reduction of said NBCHO.
16. The method of claim 13 , where the second converting comprises charging a reaction vessel with an appropriate oxidizing agent and an individual NBCHO diastereomer to effect an oxidation of said NBCHO.
17. The method of claim 14 , where the metal hydride comprises lithium aluminum hydride, alkyl aluminum hydrides, alkoxyaluminum hydrides, or dialkylamino lithium hydrides.
18. The method of claim 13 , further comprising using the analogous norbornenecarboxylic acid or alcohol in a transition metal polymerization.
19. A method for forming an essentially pure exo- and/or endo-substituted norbornene monomers, comprising:
forming a diastereomeric mixture of 5-norbornenecarbonitrile (5-NBCN) via a Diels-Alder reaction;
separating the exo- and endo-diastereomers of such diastereomeric mixture;
first converting an individual 5-NBCN diastereomer to the analogous diastereomeric norbornenecarboxaldehyde (NBCHO); and
second converting an individual NBCHO diastereomer to one of the analogous norbornenecarboxylic acid or alcohol.
20. The method of claim 1 , where the first converting comprises charging a reaction vessel with a metal hydride and an individual 5-NBCN diastereomer to effect a reduction of said 5-NBCN, and subsequently hydrolysing the reaction intermediate.