1-Benzyl-1-azonia-4-azabicyclo[2.2.2]octane Tetrahydroborate (BAAOTB) as a Selective Reducing Agent.

Content Provider	Semantic Scholar
Author	Hajipour, Abdol Reza Mohammadpoor-Baltork, I. Rahi, Allahkas
Copyright Year	2000
Abstract	The modification of sodium borohydride has attracted a great deal of attention recently.I .IO In general. the modification of the usual reducing ability of sodium borohydride has led to selective reduction of several functional groups which are otherwise inert to sodium borohydride alone. For instance, the reductions of acid chlorides to aldehydes,2 alkenes to saturated hydrocarbons,3 and alkenes to alcohols4 can be achieved by use of the combination of sodium borohydride with Cu(l), Co(ll) and Sn(IV) respectively, while such conversions can not be achieved with sodium borohydride alone. As an extension of our work in this area we have embarked on a project aimed at selecti ve reduction of imines and enarnines, reduction of oximes to the corresponding hydroxylamines, reductive ami nation of aldehydes and ketones, and reductive methylation of amines. Reduction of imines and enamines, reductive alkylation of primary and secondary amines with aldehydes and ketones and reductive methylation of aliphatic and aromatic amines with formaldehyde is widely used in amine synthesis. 11 .12 The Borch method utilising sodium cyanoborohydride l3 and zincmodified cyanoborohydride l4 being, currently, the most popular way to effect this transformation. Other methods include the use of sodium borohydride and trifluroacetic acid 15 or aqueous sulfuric acid 16, zinc borohidride l7 and zinc-modified cyanoborohydride. 18 Use of sodium cyanoborohydride and zinc cyanoborohydride risks the presence of residual cyanide in the product or work-up system. The presence of acid in the reaction medium restricts its use for molecules containing acid-sensiti ve. Recently we have reported that BAAOTB 1 reduces chiral ~-imino sul foxides to the corresponding ~-amino sulfoxides. 19 BAAOTB 1 is a highly selective agent. 20 The high chemoselectivity of this reagent encouraged us to focus our investigation for the reduction of other functional groups. This paper describes the reducing properties of 1 for reduction of imines and enarnines, reduction of oximes, reductive alkylation of primary and secondary amines with aldehydes and ketones and reductive methylation aromatic amines with formaldehy.de.
File Format	PDF HTM / HTML
DOI	10.1002/chin.200031063
Alternate Webpage(s)	http://nopr.niscair.res.in/bitstream/123456789/16695/1/IJCB%2039B(3)%20(239-242).pdf
Alternate Webpage(s)	https://doi.org/10.1002/chin.200031063
Volume Number	31
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article