Contribution to the Chemistry of Boron, 241. Improved Synthesis of 2,4,6-Trichloroborazine

1997 ◽  
Vol 52 (11) ◽  
pp. 1345-1348 ◽  
Author(s):  
Heinrich Nöth ◽  
Hermann Sachdev
Keyword(s):  
Boron Nitride ◽  
Starting Material ◽  
High Yields

Abstract 2,4,6-Trichloroborazine 2,4,6-Trichloroborazine is an important starting material for the preparation of many borazine derivatives, particularly for the parent borazine (HB=NH)3. Both are precursors for the CVD of boron nitride. Improved conditions for the synthesis of (CIB=NH)3 to give high yields are reported.

High yield and greener C–H difluoromethylation reactions using copper iodide nanoparticles/boron nitride nanosheets as a versatile and recyclable heterogeneous catalyst

2021 ◽  
Author(s):  
Udayakumar Veerabagu ◽  
Gowsika Jaikumar ◽  
Fushen Lu ◽  
Franck Quero
Keyword(s):  
Boron Nitride ◽  
Heterogeneous Catalyst ◽  
High Efficiency ◽  
High Yield ◽  
Copper Iodide ◽  
Boron Nitride Nanosheets ◽  
Greener Synthesis ◽  
High Yields ◽  
Recyclable Heterogeneous Catalyst

The 3 wt% CuI/BNNS catalyst exhibited high efficiency for C–H difluoromethylation reactions and enabled greener synthesis at high yields using cyrene as a solvent. Furthermore, the catalyst could be easily recovered and recycled for at least five cycles.

scholarly journals The synthesis of the heterocubane cluster [{CpMn}4(μ3-P)4] as a tetrahedral shaped starting material for the formation of polymeric coordination compounds

2015 ◽  
Vol 51 (70) ◽  
pp. 13474-13477 ◽  
Author(s):  
Sebastian Heinl ◽  
Konrad Kiefer ◽  
Gábor Balázs ◽  
Claudia Wickleder ◽  
Manfred Scheer
Keyword(s):  
Coordination Compounds ◽  
Starting Material ◽  
Phosphorus Containing ◽  
High Yields ◽  
Polymeric Coordination

Thermolysis of [CpMn(η6-cht)] with P4 in 1,3-diisopropylbenzene leads to the formation of the heterocubane [Cp4Mn4P4] (1) in high yields, as a rare example of ‘naked’ phosphorus containing complexes of manganese.

scholarly journals A practical synthesis of deuterated methylamine and dimethylamine

2020 ◽  
pp. 174751982096963
Author(s):  
Zhaogang Liu ◽  
Xiangyu Ren ◽  
Peng Wang
Keyword(s):  
Clinical Trials ◽  
Starting Material ◽  
New Method ◽  
The Future ◽  
Practical Synthesis ◽  
High Yields

In recent years, several deuterated drugs have entered clinical trials and have been approved for use. Deuterated methylamine and dimethylamine as important intermediates play significant roles in the preparation of deuterated drugs. In this study, we have developed a new method to prepare deuterated methylamine and dimethylamine. This method employs Boc-benzylamine as the starting material and TsOCD3 as the deuterated methylation reagent. Our method gives relatively high yields and involves simple purifications, which provide a favourable supplement for the development and synthesis of deuterated drugs in the future.

Formation of hexagonal boron nitride nanoscrolls induced by inclusion and exclusion of self-assembling molecules in solution process

Nanoscale ◽  
2014 ◽  
Vol 6 (11) ◽  
pp. 5686-5690 ◽  
Author(s):  
Da Young Hwang ◽  
Dong Hack Suh
Keyword(s):  
Boron Nitride ◽  
Hexagonal Boron Nitride ◽  
Solution Process ◽  
Simple Solution ◽  
Self Assembling ◽  
High Yields

Nanoscrolls of h-BN with high yields and reproducibility are first synthesized by a simple solution process.

scholarly journals Starting material for the breeding of easily producible lentil varieties

2021 ◽  
pp. 8-15
Author(s):  
O. M. Bezuhla ◽  
L. N. Kobyzeva
Keyword(s):  
Genetic Resources ◽  
Seed Weight ◽  
Plant Genetic Resources ◽  
Starting Material ◽  
Breeding Programs ◽  
The Czech Republic ◽  
Breeding Lines ◽  
High Yields ◽  
Wild Lentil ◽  
Intensive Work

Materials and methods. As of January 1, 2021, the National Center for Plant Genetic Resources of Ukraine has a collection comprising 1,101 lentil specimens from 54 countries, including 90 Ukrainian specimens. Of these, 17% are breeding varieties, 45% are breeding lines, 37% are trivially bred varieties and forms, and about 1% are five wild lentil species. The collection specimens were evaluated in accordance with valid methods. Our objective was to evaluate the collection for the traits that determine ease of production and to offer starting material for breeding. Our purpose was to identify sources of valuable economic characteristics for the breeding of easily producible lentil varieties. Results and discussion. Basing on the multi-year results, we selected and proposed the starting material to create easily producible lentil varieties with the following characteristics: high yields of seeds (11 macrosperma sources (Krasnohradska 5 originating from Ukraine [1000-seed weight = 73 g]; 1913 T 15 from Canada [66 g]; UD0600141 from Spain [91 g]; and others) and 25 microsperma sources (UD0600707 from Ukraine [34 g]; Miledi from Russia [38 g]; CDC Redcap from Canada [38 g]; and others)); suitability for mechanized harvesting (6 macrosperma sources (Mistseva 5 from Ukraine, Ilina from Slovakia, 1921 T 11 from Canada, and others) and 18 microsperma sources (Novourenskaya 3565 from Russia, Pozdnyaya from the Czech Republic, CDC Redwing from Canada, and others)); improved biochemical composition and high cooking qualities of seeds (3 macrosperma sources (local accessions: UD0600141 from Spain, UD0600329 from Syria, UD0600151 from Mexico) and 10 microsperma sources (local accessions: UD0600451 from Bulgaria, UD0600017 from Afghanistan, UD0600979 from Israel, and others)). Conclusions. For 30 years of intensive work of the National Center for Genetic Resources of Plants of Ukraine, divers and original staring material of lentil has been collected and studied; sources of valuable economic characteristics have been identified for breeding programs of research institutions of Ukraine and other countries

scholarly journals Diastereoselective Indole-Dearomative Cope Rearrangements by Compounding Minor Driving Forces.

2022 ◽  
Author(s):  
Subhadip De ◽  
Breanna Tomiczek ◽  
Yinuo Yang ◽  
Kenneth Ko ◽  
Ion Ghivirga ◽  
...  
Keyword(s):  
Functional Groups ◽  
Driving Forces ◽  
Starting Material ◽  
Cope Rearrangement ◽  
Proof Of Concept ◽  
Complex Architectures ◽  
Cope Rearrangements ◽  
High Yields

Reported herein is the discovery of a diastereoselective indole-dearomative Cope rearrangement. A suite of minor driving forces (substrate destabilizing effects; product stabilizing effects) are what promote this otherwise unfavorable dearomatization reaction. These include the following that work in concert to overcome the penalty for dearomatization: (i.) steric congestion in the starting material, (ii.) alkylidene malononitrile and stilbene conjugation events in the product, and (iii.) an unexpected intramolecular p–p* stack on the product side of the equilibrium. The key substrates are rapidly assembled from alkylidenemalononitriles and indole-phenylmethanol derivatives resulting in many successful examples (high yields and diastereoselectivity). The products are structurally complex bearing vicinal stereocenters generated by the dearomative Cope rearrangement. They also contain a variety of functional groups for interconversion to complex architectures. On this line, also described herein are proof-of-concept strategies for achieving enantioselectivity and conversion of the dearomative products to valuable and functionalized small drug-like molecules.

scholarly journals Side-chain opening of steroidal sapogenins to form 22-oxocholestanic skeletons. An approach to analogues of the aglycone of the potent anticancer agent OSW-1

2019 ◽  
Vol 53 (3) ◽  
Author(s):  
María A. Fernández-Herrera ◽  
Jesús Sandoval-Ramírez ◽  
Socorro Meza-Reyes ◽  
Sara Montiel-Smith
Keyword(s):  
Anticancer Agent ◽  
2D Nmr ◽  
Starting Material ◽  
Side Chain ◽  
One Pot ◽  
Mild Conditions ◽  
High Yields

The side-chain opening of 25R and 25S steroidal sapogenins to form 22-oxocholestanic skeletons is described. The transformation was produced under mild conditions providing high yields (70-87%), in a one pot procedure (some acetylated starting material is recovered). This methodology yields 17-deoxy-26-oxy analogues of the aglycone of the potent anticancer agent OSW-1. All products were fully characterized by 1D and 2D NMR; the most representative displacements are briefly discussed.    

Development of Crystallinity in Turbostratic Boron Nitride Derived from Polymeric Precursors

1991 ◽  
Vol 49 ◽  
pp. 954-955
Author(s):  
X. Qiu ◽  
A. K. Datye ◽  
T. T. Borek ◽  
R. T. Paine
Keyword(s):  
Thermal Treatment ◽  
Boron Nitride ◽  
Diffraction Pattern ◽  
Polymeric Precursors ◽  
Polymer Precursors ◽  
Diffuse Ring

Boron nitride derived from polymer precursors is of great interest for applications such as fibers, coatings and novel forms such as aerogels. The BN is prepared by the polymerization of functionalized borazine and thermal treatment in nitrogen at 1200°C. The BN powders obtained by this route are invariably trubostratic wherein the sheets of hexagonal BN are randomly oriented to yield the so-called turbostratic modification. Fib 1a and 1b show images of BN powder with the corresponding diffraction pattern in fig. 1c. The (0002) reflection from BN is seen as a diffuse ring with occational spots that come from crystals of BN such as those shown in fig. 1b. The (0002) lattice fringes of BN seen in these powders are the most characteristic indication of the crystallinity of the BN.

Structural relationships in the synthesis of cubic boron nitride thin films by ion-assisted deposition

1994 ◽  
Vol 52 ◽  
pp. 638-639
Author(s):  
D. L. Medlin ◽  
T. A. Friedmann ◽  
P. B. Mirkarimi ◽  
M. J. Mills ◽  
K. F. McCarty
Keyword(s):  
Boron Nitride ◽  
Ion Irradiation ◽  
Cubic Boron Nitride ◽  
Film Stress ◽  
Bonded Phases ◽  
Structural Relationships ◽  
Precursor Material ◽  
Pressure Synthesis ◽  
Microstructure Of The Material

The allotropes of boron nitride include two sp2-bonded phases with hexagonal and rhombohedral structures (hBN and rBN) and two sp3-bonded phases with cubic (zincblende) and hexagonal (wurtzitic) structures (cBN and wBN) (Fig. 1). Although cBN is synthesized in bulk form by conversion of hBN at high temperatures and pressures, low-pressure synthesis of cBN as a thin film is more difficult and succeeds only when the growing film is simultaneously irradiated with a high flux of ions. Only sp2-bonded material, which generally has a disordered, turbostratic microstructure (tBN), will form in the absence of ion-irradiation. The mechanistic role of the irradiation is not well understood, but recent work suggests that ion-induced compressive film stress may induce the transformation to cBN.Typically, BN films are deposited at temperatures less than 1000°C, a regime for which the structure of the sp2-bonded precursor material dictates the phase and microstructure of the material that forms from conventional (bulk) high pressure treatment.

Molecular insights on the dynamic stability of peptide nucleic acid functionalized carbon and boron nitride nanotubes

2021 ◽  
Vol 23 (1) ◽  
pp. 219-228
Author(s):  
Nabanita Saikia ◽  
Mohamed Taha ◽  
Ravindra Pandey
Keyword(s):  
Nucleic Acid ◽  
Boron Nitride ◽  
Nucleic Acids ◽  
Dynamic Stability ◽  
Peptide Nucleic Acid ◽  
Rational Design ◽  
Peptide Nucleic Acids ◽  
Boron Nitride Nanotubes ◽  
Molecular Hybrids ◽  
Single Wall Nanotubes

The rational design of self-assembled nanobio-molecular hybrids of peptide nucleic acids with single-wall nanotubes rely on understanding how biomolecules recognize and mediate intermolecular interactions with the nanomaterial's surface.

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