Selective Reductions. XI. The Reaction of Sodium Borohydride with Alkyl Halides under Solvolytic Conditions. Borohydride as a Convenient Trap for Carbonium Ions1,2

1966 ◽  
Vol 88 (7) ◽  
pp. 1473-1477 ◽  
Author(s):  
Harold M. Bell ◽  
Herbert C. Brown
Synlett ◽  
2015 ◽  
Vol 26 (08) ◽  
pp. 1055-1058 ◽  
Author(s):  
Namasivayam Palani ◽  
Sengottuvelan Balasubramanian ◽  
Tarur Dinesh

We wish to report a facile method in which a catalytic amount of bis-tri-n-butyltinoxide (TBTO) in the presence of sodium borohydride efficiently brings about the intramolecular radical cyclization of a variety of vinyl, aryl and alkyl halides to their corresponding functionalized bicyclic and tricyclic carbocycle frameworks. The methodology obviates the need for stoichiometric amounts of tin reagent normally required for radical cyclization reactions.


2020 ◽  
Author(s):  
Julian West ◽  
Alexandros S Pollatos ◽  
Radha Bam
Keyword(s):  

TAPPI Journal ◽  
2011 ◽  
Vol 10 (7) ◽  
pp. 9-16
Author(s):  
SUNG-HOON YOON ◽  
HARRY CULLINAN ◽  
GOPAL A. KRISHNAGOPALAN

We studied three process modifications to investigate their effects on the property and yield recovery capabilities of kraft pulping integrated with hemicellulose pre-extraction of southern pine. Loblolly pine chips were pre-extracted with hot water until the sugar extraction yield reached the targeted value of 10% and then subjected to conventional and modified kraft pulping. Modification included polysulfide pretreatment; polysulfide-sodium borohydride dual pretreatment, and polysulfide followed by polysulfide-sodium borohydride dual pretreatment two-stage pretreatments prior to kraft pulping. In the first modification, about 5% of the lost pulp yield (total 7%) caused by hemicellulose pre-extraction could be recovered with 15%-20% polysulfide pretreatment. Complete recovery (7%) was achieved with simultaneous pretreatment using 15% polysulfide and 0.5% sodium borohydride with 0.1% anthraquinone in polysulfide-sodium borohydride dual pretreatment. Two-stage pretreatment using recycled 15% polysulfide followed by simultaneous treatment of 6% polysulfide and 0.4%–0.5% sodium borohydride with 0.1% anthraquinone also achieved 100% yield recovery. Continuous recycling of 15% polysulfide employed in the two-stage process modification maintained its yield protection efficiency in a repeated recycling cycle. No significant changes in paper strength were found in handsheets prepared from the three process modifications, except for a minor reduction in tear strength.


2019 ◽  
Vol 29 (3) ◽  
Author(s):  
Mai Ngọc Tuan Anh

Silver nanoplates (SNPs) having different size were synthesized by a seed-mediated method. The seeds -silver nanoparticles with 4 – 6 nm diameters were synthesized first by reducing silver nitrate with sodium borohydride in the present of Trisodium Citrate and Hydrogen peroxide. Then these seeds were developed by continue reducing Ag\(^+\) ions with various amount of L-Ascorbic acid to form SNPs. Our analysis showed that the concentratrion of L-Ascorbic acid, a secondary reducing agent, played an important role to form SNPs. In addition, the size and in-plane dipole plasmon resonance wavelenght of silver nanoplates were increased when the concentration of added silver nitrate increased. The characterization of SNPs were studied by UV-Vis, FE-SEM, EDS and TEM methods.


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