Abstract

Lithium aminoborohydride (LAB) reagents are powerful reducing agents, comparable to lithium aluminum hydride (LAH) and Vitride, yet selective in their reducing properties. They are thermally stable and much less water reactive than LAH and Vitride.

LAB reagents reduce a wide range of functional groups: aldehydes, ketones, esters, lactones, amides, anhydrides, oximes, nitriles, epoxides and halides. These compounds are readily reduced in one hour or less at ambient temperature. Carboxylic acids are not reduced by LAB reagents.

LAB reagents have recently shown dual properties as both hydride and amine transfer agents. They promote nucleophilic aromatic substitution of their amine moiety in 2-halobenzonitriles, performing a unique tandem amination- reduction reaction.

Publications:

Pasumansky, Lubov; Goralski, Christian T.; Singaram, Bakthan. Lithium Aminoborohydrides: Powerful, Selective, Air-Stable Reducing Agents. Organic Process Research & Development (2006), 10(5), 959-970.

Pasumansky, Lubov; Singaram, Bakthan; Christian T. Goralski. Recent advances in the chemistry of lithium aminoborohydrides. Aldrichimica Acta (2005), 38(2), 61-65.

Pasumansky, Lubov; Hernandez, Armando R.; Gamsey, Soya; Goralski, Christian T.; Singaram, Bakthan. Synthesis of aminopyridines from 2-fluoropyridine and lithium amides. Tetrahedron Letters (2004), 45(34), 6417-6420.

Thomas, Shannon; Huynh, Tai; Enriquez-Rios, Vanessa; Singaram, Bakthan.
Aminoborohydrides. 14. Lithium Aminoborohydrides in the Selective Reduction
or Amination of Alkyl Methanesulfonate Esters. Org. Lett. 2001, 3, 3915-3918.

Thomas, Shannon; Collins, Christopher J.; Cuzens, Jennifer R.; Spiciarich,
David; Goralski, Christian T.; Singaram, Bakthan. Aminoborohydrides. 12.
Novel tandem SNAr amination-reduction reactions of 2-halobenzonitriles with
lithium lithium N,N-dialkylaminoborohydrides. J. Org Chem. 2001, 66, 1999-2004.

Thomas, Shannon; Collins, Christopher J.; Goralski, Christian T.; Singaram,
Bakthan. Two in one reagents. Chemical Innovation 2000, 30, 31-36.