Sodium borohydride, Sodium tetrahydroborate

Name Reactions

Recent Literature

Manganese dioxide is employed as an in situ oxidant for the one-pot conversion of alcohols into imines. In combination with polymer-supported cyanoborohydride (PSCBH), a one-pot oxidation-imine formation-reduction sequence enables alcohols to be converted directly into both secondary and tertiary amines.
L. Blackburn, R. J. K. Taylor, Org. Lett., 2001, 3, 1637-1639.

In the reductive amination of some aldehydes with primary amines where dialkylation is a problem, a stepwise procedure involving imine formation in MeOH followed by reduction with NaBH₄ was developed.
A. F. Abdel-Magid, K. G. Carson, B. D. Harris, C. A. Maryanoff, R. D. Shah, J. Org. Chem., 1996, 61, 3849-3862.

A simple and convenient procedure allows the reductive amination of aldehydes and ketones using sodium borohydride as reducing agent and boric acid, p-toluenesulfonic acid monohydrate or benzoic acid as activator under solvent-free conditions.
B. T. Cho, S. K. Kang, Tetrahedron, 2005, 61, 5725-5734.

B. T. Cho, S. K. Kang, Tetrahedron, 2005, 61, 5725-5734.

Copper(II) trifluoromethanesulfonate catalyzed a mild amidation of cyclic ethers with iminoiodanes with good yields and selectivity. A subsequent reductive ring-opening of the tosylamidated products gives α,ϖ-amino alcohols.
L. He, J. Yu, J. Zhang, X.-Q. Yu, Org. Lett., 2007, 9, 2277-2280.

Phthalimides are converted to primary amines in an efficient, two-stage, one-flask operation using NaBH₄/2-propanol, then acetic acid. Phthalimides of α-amino acids are smoothly deprotected with no measurable loss of optical activity.
J. O. Osby, M. G. Martin, B. Ganem, Tetrahedron Lett., 1984, 25, 2093-2096.

A high-yielding, asymmetric synthesis of novel 4-formyl-1-(2- and 3-haloalkyl)azetidin-2-ones was developed as valuable starting materials for the synthesis of different enantiomerically enriched bicyclic azetidin-2-ones, such as piperazine, morpholine, and 1,4-diazepane annulated β-lactam derivatives.
W. Van Brabandt, M. Vanwalleghem, M. D'hooghe, N. De Kimpe, J. Org. Chem., 2006, 71, 7083-7086.

The selective aldimine cross-coupling represents a simple and flexible method for the synthesis of highly substituted unsymmetrical 1,2-diamines. In addition, either the syn- or anti-configurated vicinal diamine can be obtained, depending on the choice of the workup and reduction conditions.
C. Kison, N. Meyer, T. Opatz, Angew. Chem., 2005, 117, 5807-5809.

A simple method for the chemo- and regioselective, direct catalytic allylic alkylation of aldehydes and cyclic ketones has been developed. The combination of palladium and enamine catalysis furnished α-allylic alkylated aldehydes and cyclic ketones in high yields.
I. Ibrahem, A. Córdova, Angew. Chem. Int. Ed., 2006, 45, 1952-1956.

A novel, convenient and stereoselective synthesis of trisubstituted E-alkenones has been achieved by InCl₃-mediated chemoselective reduction of Baylis-Hillman adducts with NaBH₄ as reductant.
B. Das, J. Banerjee, N. Chowdhury, A. Majhi, H. Holla, Synlett, 2006, 1879-1882.

Optically pure C₂-symmetrical cyclic amines were efficiently synthesized from the corresponding diols obtained from an enantioselective borohydride reduction of diketones in the presence of a chiral β-ketoiminato cobalt(II) catalyst.
M. Sato, Y. Gunji, T. Ikeno, T. Yamada, Synthesis, 2004, 1434-1438.

The scope of nickel boride mediated reduction of nitriles has been extended further to allow the preparation of Boc protected amines via a mild catalytic process. The toxicity of this procedure is greatly reduced due to the catalytic use of nickel(II) chloride in combination with excess sodium borohydride. This protocol is practical and tolerates air and moisture. Although the yield is sometimes moderate, the cleanliness of the method is exceptional. No further purification is necessary after work-up.
S. Caddick, D. B. Judd, A. K. de K. Lewis, M. T. Reich, M. R. V. Williams, Tetrahedron, 2003, 59, 5417-5423.

A selective and direct access to secondary amines by reductive mono-N-alkylation of primary amines with carbonyl compounds in the presence of Ti(i-PrO)₄ and NaBH₄ gave exclusively secondary amines.
H. J. Kumpaty, S. Bhattacharyya, E. W. Rehr, A. M. Gonzalez, Synthesis, 2003, 2206-2210.

An efficient, general procedure for highly chemoselective reductive mono-alkylation of ammonia with ketones is reported. Treatment of ketones with ammonia in ethanol and titanium(IV) isopropoxide, followed by in situ reduction with sodium borohydride, and a simple workup afforded primary amines in good to excellent yields. Reductive alkylation of ammonia with aldehydes, on the other hand, afforded the corresponding symmetrical secondary amines selectively.
B. Miriyala, S. Bhattacharyya, J. S. Williamson, Tetrahedron, 2004, 60, 1463-1471.

A catalytic, direct asymmetric cross-aldol reaction of two different aldehydes in the presence of water is catalyzed by a novel combined proline-surfactant organocatalyst. Neither an organic cosolvent nor additional acid is necessary.
Y. Hayashi, S. Aratake, T. Okano, J. Takahashi, T. Sumiya, M. Shoji, Angew. Chem. Int. Ed., 2006, 45, 5527-5529.

Reliable and Versatile Synthesis of 2-Aryl-Substituted Cinnamic Acid Esters
A. Ianni, S. R. Waldvogel, Synthesis, 2006, 2103-2112.

Salicylic acids and alcohols can be reduced to 2-methylphenols by a simple two steps procedure. Reaction conditions were optimized carrying out a study on the solvent effect and the amount of the reducing agent. The improved procedure resulted particularly useful in the synthesis of deuterated building blocks of biological interest.
F. Mazzini, P. Salvadori, Synthesis, 2005, 2479-2481.

Treatment of γ-hydroxy-α,β-acetylenic esters with sodium borohydride or Red-Al gave γ-hydroxy-α,β-alkenoic esters by means of trans-selective addition of two hydrogen atoms or a hydrogen atom and an iodine atom across the triple bond.
C. T. Meta, K. Koide, Org. Lett., 2004, 6, 1785-1787.

Treatment of 3-[(alkoxycarbonyl)alkyl]-substituted conjugated cycloalkenones with diisobutylaluminum hydride at -78 °C followed by acid quenching furnishes spiro ethers, whereas the corresponding 3-(carboxyalkyl)-substituted cycloalkenones generate spiro lactones upon reaction with sodium borohydride at 30 °C followed by acid quenching.
M.-C. P. Yeh, Y.-C. Lee, T.-C. Young, Synthesis, 2006, 3621-3624.

Sodium borohydride in the presence of iodine in anhydrous THF converts various sulfoxides to their thioethers in excellent yields. A chemoselective deoxygenation of sulfoxides can be achieved in the presence of other reducible functional groups such as esters, nitriles and double bonds.
B. Karimi, D. Zareyee, Synthesis, 2003, 335-336.

Dichloroindium hydride (Cl₂InH) generated in situ from the combination of a catalytic amount of indium(III) chloride and sodium borohydride in acetonitrile reduces activated vic-dibromides to the corresponding (E)-alkenes in excellent yields.
B. C. Ranu, A. Das, A. Hajira, Synthesis, 2003, 1012-1014.

B. C. Ranu, A. Das, A. Hajira, Synthesis, 2003, 1012-1014.

Pd/C in aqueous alcohol with molecular oxygen, sodium borohydride, and potassium carbonate efficiently oxidized benzylic and allylic alcohols. Sodium borohydride allows a remarkable reactivation of active sites of the Pd surface.
G. An, M. Lim, K.-S. Chun, H. Rhee, Synlett, 2007, 95-98.