Amine-boranes bearing borane-intolerant functionalities

Abstract

Disclosed herein is the preparation of functional group containing amine-boranes from the corresponding amines. The mild reaction conditions allow for the direct preparation of several hitherto inaccessible amine-boranes containing a functional moiety, such as but not limited to, alkene, alkyne, hydroxyl, thiol, acetal, ester, amide, nitrile, nitro, and alkoxysilane.

What is claimed is: 
     
         1 . An amine-borane prepared according to the process of
 a. preparing about two equivalent of sodium borohydride and about four equivalents of sodium bicarbonate;   b. adding about one equivalent amine, wherein said amine carries a functional group selected from the group consisting of alkene, alkyne, nitro, hydroxyl, thiol, cyano (nitrile), acetal, ester, amide, and alkoxysilane;   c. adding THF (tetrahydrofuran) with stirring to afford a reaction mixture of said amine at about 0.5˜2 M (moles/liter);   d. adding dropwise about 3˜4 equivalents of water in a THF solution to the reaction mixture of step c under vigorous stirring; and   e. stirring for about 4 to 48 hours to afford an amine-borane, wherein said amine-borane may carry a functional group selected from the group consisting of alkene, alkyne, nitro, hydroxyl, thiol, cyano (nitrile), acetal, ester, amide, and alkoxysilane.   
     
     
         2 . The amine-borane according to  claim 1 , wherein said process is carried out at an ambient temperature. 
     
     
         3 . The amine-borane according to  claim 1 , wherein said water-THF solution is about 14% (v/v) water in THF. 
     
     
         4 . The amine-borane according to  claim 1 , wherein said amine may be a monoamine or a diamine. 
     
     
         5 . The amine-borane according to  claim 1 , wherein said amine-borane is part of an aromatic molecule, an aliphatic molecule, or a combination thereof. 
     
     
         6 . The amine-borane according to  claim 1 , wherein said amine-borane is part of a cyclic structure, a linear structure, a branched structure, or a combination thereof. 
     
     
         7 . The amine-borane according to  claim 1 , wherein said water in a THF solution is about four equivalents of said amine when said amine carries a functional group selected from the group consisting of alkene, alkyne, nitro, hydroxyl, thiol, cyano (nitrile), acetal, ester, amide, and alkoxysilane. 
     
     
         8 . The amine-borane according to  claim 1 , wherein said amine carries one or more functional groups selected from the group consisting of alkene, alkyne, nitro, hydroxyl, thiol, cyano (nitrile), acetal, ester, amide, and alkoxysilane. 
     
     
         9 . The amine-borane according to  claim 1 , wherein said amine-borane carries one or more functional groups selected from the group consisting of alkene, alkyne, nitro, hydroxyl, thiol, cyano (nitrile), acetal, ester, amide, and alkoxysilane.