Open-flask hydroboration and the use thereof

Patent metadata

Field	Value
Publication number	US-10384994-B2
Application number	US-201715680258-A
Country	US
Kind code	B2
Filing date	Aug 18, 2017
Priority date	Aug 19, 2016
Publication date	Aug 20, 2019
Grant date	Aug 20, 2019

Abstract

The present disclosure generally relates to a process for hydroboration of an alkene or alkyne using ammonia borane (AB). In particular, the present invention relates to hydroboration of an alkene or alkyne in the presence of air or moisture, and a clean process for facile preparation of an alcohol by oxidizing the organoborane so formed with hydrogen peroxide. The products, including aminodialkylboranes, ammonia trialkylborane complexes, as well as various alcohols so prepared, are within the scope of this disclosure.

First claim

What is claimed is:

1. A process for preparing an alcohol, primary, secondary, or vicinal diol using an alkene or alkyne, comprising the steps of
a. preparing a solution of an ammonia borane (AB);
b. adding an alkene or alkyne to said AB solution;
c. refluxing with heating and stirring to afford an organoborane, wherein the effectiveness of this process is not affected by the presence of air or moisture;
d. cooling the reaction mixture to about 0° C. and then adjusting the pH of the solution to basic with a NaOH solution; and
e. oxidizing said organoborane by adding about three equivalents of H 2 O 2 to afford an alcohol.

2. The process of claim 1 , wherein the molar ratio of said AB to said alkene or alkyne ranges from about 2 to about 0.2.

3. The process of claim 1 , wherein the molar ratio of said AB to said alkyne is about 2 for a vicinal diol.

4. The process of claim 1 , wherein the molar ratio of said AB to said alkene is about 0.3 for a primary alcohol.

5. The process of claim 1 , wherein the molar ratio of said AB to said alkene is about 0.5 for a secondary alcohol.

6. The process of claim 1 , wherein said solution of an ammonia borane is prepared using THF (tetrahydrofuran).

7. The process of claim 6 , wherein said ammonia borane in THF has a concentration of about 0.5˜2 M (moles/liter).

8. The process of claim 1 , wherein said refluxing is performed at about 90° C.

9. The process of claim 1 , wherein said alkene or alkyne is part of an aromatic molecule, an aliphatic molecule, or a combination thereof.

10. The process of claim 1 , wherein said alkene or alkyne is part of a cyclic structure, a linear structure, a branched structure, or a combination thereof.

Assignees

• Purdue Research Foundation

Inventors

• Ramachandran P Veeraraghavan
• Kulkarni Ameya Sanjay
• Drolet Michael Patrick

Classifications

• C07F5/027

  Organoboranes and organoborohydrides · CPC title

• C07C2602/20

  the ring system containing seven carbon atoms · CPC title

• C07F7/1876

  by reactions involving the formation of Si-C linkages · CPC title

• C07C31/137

  polycyclic with condensed ring systems · CPC title

• C07C29/03

  by addition of hydroxy groups to unsaturated carbon-to-carbon bonds, e.g. with the aid of H2O2 (by simultaneous introduction of -OH groups and halogens C07C29/64) · CPC title