نتایج جستجو برای: acid base catalyst

تعداد نتایج: 1012226  

Journal: :Chemical & pharmaceutical bulletin 2000
M Takamura Y Hamashima H Usuda M Kanai M Shibasaki

A general asymmetric Strecker-type reaction is reported, catalyzed by the Lewis acid-Lewis base bifunctional catalyst 1. The reaction of trimethylsilyl cyanide (TMSCN) with various fluorenyl imines, including n-aldimines and alpha,beta-unsaturated imines, proceeds with good to excellent enantioselectivities in the presence of a catalytic amount of phenol as additive (20 mol%) (catalytic system ...

2012
Ping Li Chang-Yan Cao Zhe Chen Hua Liu Yu Yu Wei-Guo Song

The cascade reaction sequence is a fascinating subject in catalysis. A rationally designed cascade reaction sequence can simplify the synthetic route, reduce the amount of waste and lower the operation cost. The key for a successful cascade reaction sequence is the multifunctional catalyst. With a suitable multifunctional catalyst, multiple synthesis steps can proceed in one pot with high yield...

2014
Hwei Voon Lee Joon Ching Juan Nurul Fitriyah Binti Abdullah Rabiah Nizah MF Yun Hin Taufiq-Yap

BACKGROUND Transesterification catalyzed by solid base catalyst is a brilliant technology for the noble process featuring the fast reaction under mild reacting condition in biodiesel production. Heterogeneous base catalysts are generally more reactive than solid acid catalysts which require extreme operating condition for high conversion and biodiesel yield. In the present study, synthesis of b...

Journal: :Journal of the American Chemical Society 2013
Alan H Cherney Nathaniel T Kadunce Sarah E Reisman

The first enantioselective Ni-catalyzed reductive acyl cross-coupling has been developed. Treatment of acid chlorides and racemic secondary benzyl chlorides with a Ni(II)/bis(oxazoline) catalyst in the presence of Mn(0) as a stoichiometric reductant generates acyclic α,α-disubstituted ketones in good yields and high enantioselectivity without requiring stoichiometric chiral auxiliaries or prege...

2013
Richard Heck

The Suzuki cross-coupling reaction is about 30 years old and represents a smooth method for creating carbon-carbon bonds. Typically, in the Suzuki reaction aryl halides are combined with an aryl boronic acid or boronic ester in the presence of a Pd(0) catalyst and base to afford a variety of biaryl compounds (Scheme 1). These biphenyl templates are very common in non-steroidal anti-inflammatory...

2015
Sanjib Kumar Karmee Raffel Dharma Patria Carol Sze Ki Lin

Fossil fuel shortage is a major challenge worldwide. Therefore, research is currently underway to investigate potential renewable energy sources. Biodiesel is one of the major renewable energy sources that can be obtained from oils and fats by transesterification. However, biodiesel obtained from vegetable oils as feedstock is expensive. Thus, an alternative and inexpensive feedstock such as wa...

Bamboo is one of the important biopolymers which is used in chemistry. In this work, for the first time, a solid acid catalyst from bamboo was prepared from the reaction of sawdust bamboo and chlorosulfonic acid. Relevant properties of catalyst were investigated by FT-IR, XRD, SEM and TGA. The sulfonated bamboo (bamboo-SO3H) with several acid functional groups was utilized as highly ...

Journal: :international journal of environmental research 2014
m.a. abdoli f. mohamadi b. ghobadian e. fayyazi

using low-cost feedstocks such as rendered animal fats in biodiesel production willreducebiodieselexpenditures. one of the low-cost feedstocksfor biodiesel production could be the fatextracted from poultry feathers producedin slaughterhouses abundantly. this paper describes a new andenvironmentally friendly process for developing biodiesel production technology from feather waste producedin pou...

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