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DOI: 10.1055/s-0029-1219952
Sodium Triacetoxyborohydride
Publication History
Publication Date:
11 June 2010 (online)
Introduction
Sodium triacetoxyborohydride [Na(OAc)3BH, abbreviated as STAB-H] is a versatile reagent in organic synthesis. In addition to its superior ability in effecting reductive amination of aldehydes and ketones, it can reduce N-heterocycles (indoles, quinolines, and isoquinolines), imines, enamines, oximes, amides, aryl ketones, acetals, and other substrates. [¹]
STAB-H is a milder and more selective reducing agent than NaBH4. The mild nature of STAB-H may be attributed both to the bulky nature of the reagent and to the inductive electron-withdrawing ability of the three acetoxy groups which stabilize the boron-hydrogen bond. [²] It has more advantages over Na(CN)BH3 also due to the lack of toxicity.
The preparation of triacetoxyborohydride was first performed by Wartik and Pearson through the reaction of NaBH4 and CO2 (Scheme [¹] ). [³] Furthermore, it can be also generated in situ from NaBH4 and acetic acid. Aldehydes, but not ketones, are smoothly reduced to alcohols with STAB-H, prepared from sodium borohydride and acetic acid in benzene [4] or in N,N-dimethylacetamide. [5]
Scheme 1
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Gribble GW. Org. Process Res. Dev. 2006, 10: 1062 - 2
Taft RW.Deno NC.Skell PS. Ann. Rev. Phys. Chem. 1958, 9: 287 - 3
Wartik T.Pearson RK. J. Am. Chem. Soc. 1955, 77: 1075 - 4
Gribble GW.Ferguson DC. J. Chem. Soc., Chem. Commun. 1975, 535 - 5
Lam TT.Bagner C.Tuma L. Thermochim. Acta 2005, 426: 109 - 6
Boros EE.Thompson JB.Katamreddy SR.Carpenter AJ. J. Org. Chem. 2009, 74: 3587 - 7
Mapes CM.Mani NS. Org. Process Res. Dev. 2007, 11: 482 - 8
Brooks PR.Caron S.Coe JW.Ng KK.Singer RA.Vazquez E.Vetelino MG.Watson Jr.H H.Whritenour DC.Wirtz MC. Synthesis 2004, 1755 - 9
Zhang J.Blazecka PG.Davidson JG. Org. Lett. 2003, 5: 553 - 10
Dondoni A.Massi A.Minghini E. Synlett 2006, 539 - 11
Sessler JL.Aguilar A.Sanchez-Garcia D.Seidel D.Kohler T.Arp F.Lynch VM. Org. Lett. 2005, 7: 1887 - 12
Wu G.Wong Y.Steinman M.Tormos W.Schumacher DP.Love GM.Shutts B. Org. Process Res. Dev. 1997, 1: 359 - 13
Calvet S.David O.Vanucci-Bacque C.Fargeau-Bellassoud M.-C. Tetrahedron 2003, 59: 6333 - 14
Reddy LR.Saravanan P.Corey EJ. J. Am. Chem. Soc. 2004, 126: 6230