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Tetrahedron Letters
Application of natural feedstock extract: the Henry reaction
a
a
b
Naresh Surneni , Nabin C. Barua and Bishwajit Saikia*
a
Natural Products Chemistry Division, CSIR-North East Institute of Science and Technology, Jorhat–785006, Assam, India.
Department of Chemistry, Dibrugarh University, Dibrugarh–786004, Assam, India.
b
ARTICLE INFO
ABSTRACT
Article history:
Received
Received in revised form
Accepted
For the first time, we have successfully performed the Henry reaction in neat ‘Natural Feedstock
Extract’ at room temperature. Herein, we used two most abundant natural feedstock extracts
such as ‘Water Extract of Banana’ (WEB) and ‘Water Extract of Rice Straw Ash’’ (WERSA).
This protocol is highly advantageous owing to the employment of natural feedstock as green
reaction media results significant novelty and advance with respect to green and sustainable
chemistry.
Available online
Keywords:
Henry reaction
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009 Elsevier Ltd. All rights reserved.
Natural Feedstock
Water Extract of Banana (WEB)
Water Extract of Rice Straw Ash (WERSA)
Nitromethane
The construction of carbon–carbon bonds is an essential
aspect of synthetic organic chemistry. The Henry reaction which
is also referred to as the nitro-aldol reaction is a classic carbon–1
carbon bond formation reaction in organic chemistry.
Essentially, this reaction describes the coupling of a nucleophilic
nitro alkane with an electrophilic aldehyde or ketone to produce a
these extracts (WEB and WERSA) contain potassium, sodium,
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carbonate and hydroxide and therefore they are basic in nature.
Wang et al. have reported a nitro-aldol (or Henry) reaction in
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aqueous solution using double-stranded DNA of natural origin.
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It should also be mentioned that nitroaldol (Henry) reaction of
aromatic aldehydes with nitromethane using human serum
albumin (HSA) in water has been reported by Matsumoto and his
highly synthetically useful β-nitro alcohol. Nowadays, the
important aspect which is receiving growing attention is the use
of alternative reaction media that avoid the problems associated
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with many of the traditional volatile organic solvents. The use of
co-workers. Similarly, Pawar’s group has reported the cesium
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hazardous solvents in chemical industry is associated with a
variety of indirect environmental impacts such as non-renewable
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fluorides in ionic liquid [bmim][BF ] promoted Henry reaction.
Besides, Le and his co-workers developed another method for the
Henry reaction of aromatic aldehydes and nitroalkanes performed
by catalyst of Lipase A from Aspergillus niger in organic/water
resource reduction as
a result of petrochemical solvent
production, air emissions due to solvent incineration or high
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energy investment for solvent recycling processes. Therefore,
medium. Recently Asano et al. reported for the first time an R-
the ability to efficiently carry out organic reactions in more
environmentally friendly solvents remains an important object of
green chemistry research. It means that wherever practicable,
synthetic methods should be designed to use and generate
substances that possess little or no toxicity to animal health and
selective hydroxy nitrile lyase from Arabidopsis thaliana.
However, a maximum of 30% yield was achieved and the
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reaction is highly substrate dependent. Lin et al. found d-
aminoacylase from E. coli to be the most effective catalyst for the
addition of either nitromethane or nitroethane to a range of
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the environment. Our interest is using highly abundant natural
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aliphatic, aromatic and heteroaromatic aldehydes. Practical
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feedstock extract to replace organic solvents in Henry reaction
application of these methods was limited owing to the relatively
harsh reaction conditions such as the utilization of toxic organic
solvents, long reaction time, elevated reaction temperature, use of
expensive, less abundant catalysis, requirement of large amount
of catalysts loading, use of additives/promoters and limited
substrate scope.
because feedstock extract endows the reaction with green and
safe properties. The strategy to use Water Extract of Banana’
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(WEB)
and ‘Water Extract of Rice Straw Ash’’ (WERSA) in
catalysis is the key challenge of this work and represent an
enormous potential feedstock extracts for the production of
chemicals. The preparation of these natural feedstock extracts
often involves three steps: drying the banana parts/rice straw
followed by burning them to ash and subsequent addition of
water to the ash, mixed well and then filtered. The filtrates are
abbreviated as WEB and WERSA. Literature reports reveal that
Considering the promise of Henry reaction and the need to
make industrial processes more environmentally friendly, we
advance this catalytic concept to describe the first Henry reaction
of various aliphatic/aromatic aldehydes on the use of novel
aqueous extract such as WEB and WERSA. To the best of our
knowledge this is the first report of the Henry reaction in neat
WEB/WERSA at room temperature without using any external
*
Corresponding author. Tel.: +91 9954314676.
E-mail: bishwajitsaikia@gmail.com (B. Saikia).