- Synthesis and crystal structure determination of [H2-cryptand 222](Br3)2: A unique tribromide catalyst for the catalytic chemoselective N-boc protection of amines
-
The organic tribromide, [H2-cryptand 222](Br3) 2 was synthesized and characterized by X-ray crystallography, and was utilized as an active catalyst for the N-boc protection of amines. The method is general for the preparation of N-boc derivatives of aliphatic (acyclic and cyclic), aromatic, primary and secondary amines. We also applied our new reaction protocols for the N-boc protection of some new amines and spectral and physical data for the obtained products are reported.
- Chehardoli, Gholamabbas,Zolfigol, Mohammad Ali,Khakyzadeh, Vahid,Golbedaghi, Reza,Hall, Nikita A.,Blackman, Allan G.
-
-
Read Online
- Sugar-based hydrophilic polyurethanes and polyureas
-
Novel linear homogeneous polyurethanes and polyureas with enhanced hydrophilic character have been successfully prepared from sugar-based monomers having their hydroxyl groups free or partially protected. By the reaction of primary hydroxyl groups of xyli
- Begines, Belen,Zamora, Francisca,Roffe, Isaac,Mancera, Manuel,Galbis, Juan A.
-
-
Read Online
- PRODUCTION METHOD FOR AMIDATE COMPOUND
-
A method for producing an amidate compound represented by Formula (3), comprising reacting a urethane compound represented by Formula (1) with a carboxylate compound represented by Formula (2): (in the formulas, A, n, R1, R2, R3, R4, R5, R6, X, and a are as described in the Description).
- -
-
Paragraph 0171-0173
(2020/02/13)
-
- Amidate compound, catalyst for polyurethane production, and method for producing polyurethane resin
-
Provided is an amidate compound represented by the formula (1): wherein A is a substituted or unsubstituted hydrocarbon group, n is an integer of 1 or more, and D is a nitrogen-containing organic group represented by the formula (2): wherein R1, R2, and R3 are the same or different, and are each a hydrocarbon group that may contain a heteroatom; some or all of R1, R2, and R3 may be bonded together to form a ring structure; X is a nitrogen atom, an oxygen atom, or a sulfur atom; and a is 0 or 1, wherein a is 1 when X is a nitrogen atom, and a is 0 when X is an oxygen atom or a sulfur atom.
- -
-
Page/Page column 130
(2020/07/09)
-
- Fluoride-Catalyzed Deblocking: A Route to Polymeric Urethanes
-
We report a fluoride-catalyzed deblocking of urethanes as “blocked” isocyanates. Organic and inorganic sources of fluoride ion proved effective for deblocking urethanes and for converting polyurethanes to small molecules. Distinct from conventional deblocking chemistry involving organometallic compounds and high temperatures, the method we describe is metal-free and operates at or slightly above room temperature. The use of fluorescent blocking agents enabled visual and spectroscopic monitoring of blocking/deblocking reactions, and the selected conditions proved applicable to urethanes containing a variety of blocking groups. The method additionally enabled a one pot deblocking and polymerization with α,ω-diols. Overall, this deblocking/polymerization strategy offers a convenient and efficient solution to problems that have limited the breadth of applications of polyurethane chemistry.
- Sheri, Madhu,Choudhary, Umesh,Grandhee, Sunitha,Emrick, Todd
-
supporting information
p. 4599 - 4602
(2018/03/28)
-
- Preparation, characterization and application of 1,4-disulfopiperazine-1,4-diium chloride ([Piper-(SO3H)2]·2Cl) as an efficient dicationic ionic catalyst for the N-Boc protection of amines
-
In this work, 1,4-disulfopiperazine-1,4-diium chloride ([Piper-(SO3H)2]·2Cl), as a novel Br?nsted acidic ionic catalyst is synthesized and characterized using a series of techniques including FT-IR, TGA, DTA, SEM, pH analysis and Hammett acidity function. This substance can significantly catalyze the N-Boc protection of amines without solvent interference at room temperature. The advantages of this manner are chemoselectivity, short reaction times, suitable yields, excellent yields of the products, without solvent interference and ease of preparation as well as reusability of the catalyst.
- Koodehi, Tahereh Ghauri,Shirini, Farhad,Goli-Jolodar, Omid
-
p. 443 - 456
(2017/01/10)
-
- Nano-ferrous ferric oxide (nano-Fe3O4): Powerful, reusable, and stable catalyst for N-Boc protection of amines
-
Nano-ferrous ferric oxide (nano-Fe3O4) efficiently catalyzed N-boc protection of amines in high yields and acceptable reaction times. Nano-Fe3O4 was applied as an efficient, green, heterogeneous and reusable magnetite catalyst. Clean reaction, simple purification, short reaction time and high yield were some other advantages of this compound.
- Zolfigol, Mohammad Ali,Moosavi-Zare, Ahmad Reza,Moosavi, Parvin,Khakyzadeh, Vahid,Zare, Abdolkarim
-
p. 962 - 966
(2013/11/06)
-
- {[[K.18-Crown-6]Br3}n: A tribromide catalyst for the catalytic protection of amines and alcohols
-
{[K.18-Crown-6]Br3}n, a unique tribromide-type catalyst, was utilized for the N-boc protection of amines and trimethylsilylation (TMS) and tetrahydropyranylation (THP) of alcohols. The method is general for the preparation of N-boc derivatives of aliphatic (acyclic and cyclic) and aromatic, and primary and secondary amines and also various TMS-ethers and THP-ethers. The simple separation of the catalyst from the product is one of the many advantages of this method.
- Chehardoli, Gholamabbas,Zolfigol, Mohammad Ali,Derakhshanpanah, Fateme
-
p. 1730 - 1733
(2013/10/21)
-
- RADIATION-SENSITIVE RESIN COMPOSITION, METHOD FOR FORMING A RESIST PATTERN, COMPOUND, AND POLYMER
-
A radiation-sensitive resin composition includes a first polymer that includes a repeating unit having an acid-labile group and becomes alkali-soluble upon dissociation of the acid-labile group, and a radiation-sensitive acid-generating agent. The acid-labile group has a structure shown by a general formula (1). R1 represents a methyl group or the like, R2 represents a hydrocarbon group that forms a cyclic structure, R3 represents a fluorine atom or the like, R4 represents a carbon atom, and n1 is an integer from 1 to 7.
- -
-
-
- Mild and high-yielding molybdenum(VI) dichloride dioxide-catalyzed formation of Mono-, Di-, Tri-, and tetracarbamates from alcohols and aromatic or aliphatic isocyanates
-
Both molybdenum(VI) dichloride dioxide (MoO2Cl2) and its dimethylformamide (DMF) complex catalyze the addition of alcohols to isocyanates giving carbamates. Most additions proceeded to completion at room temperature within 20 min using as little as 0.1 mol% of the catalyst when working on a 1-mmol scale or just 100 ppm working on a 20-mmol scale. Sterically encumbered substrates reacted to completion when 1 mol% of the catalyst was employed. Diols, triols, and tetraols reacted with monoisocyanates likewise, as did monofunctional alcohols and diisocyanates. These pairings furnished di-, tri-, tetra-, and dicarbamates, respectively. Reactants, which were poorly soluble in CH2Cl2 at room temperature required elevating the temperature and possibly choosing a higher-boiling solvent (ClCH 2CH2Cl, DMF) as well. Additions of diols to diisocyanates were feasible, too, giving polycarbamates as we presume. Copyright
- Stock, Christian,Brueckner, Reinhard
-
p. 2309 - 2330
(2012/11/07)
-
- Asymmetrical diaromatic guanidinium/2-aminoimidazolinium derivatives: Synthesis and DNA affinity
-
In this paper we report the synthesis of three families of new amidine-based aromatic derivatives as potential DNA minor groove binding agents for the treatment of cancer. The preparation of monoguanidine, mono-2-aminoimidazoline, and asymmetric diphenylg
- Nagle, Padraic S.,Rodriguez, Fernando,Kahved?i?, Amila,Quinn, Susan J.,Rozas, Isabel
-
supporting information; experimental part
p. 7113 - 7121
(2010/04/28)
-
- Novel material forming supramolecular structures, process and uses
-
The invention relates to novel material, forming supramolecular structures below its transition temperature, which contains at least one C=O and/or C=S group and at least one N—H, O—H and/or S—H group and wherein the material has the structure [in-line-formulae]A(—X—B)n ??(1)[/in-line-formulae] wherein A is a cyclic, aromatic and/or aliphatic group, n being a number of 1 to 4, —X—B is, if n is 2, the same or different, and if n is 3 or 4, the same, partly the same or different and has one of the structures (2) to (4) [in-line-formulae]NH—C(Y)—Y—B ??(2)[/in-line-formulae] [in-line-formulae]—NH—C(Y)—NR—B ??(3)[/in-line-formulae] [in-line-formulae]—Y—C(Y)—NR—B ??(4)[/in-line-formulae] with Y being an Oxygen and/or Sulfur atom, B being an organic group with at least one heteroatom, where the heteroatom is bound to at least two carbon atoms when B is linear or cyclic, and where the heteroatom is bound to at least one carbon atom when B is branched, and R being a Hydrogen atom, a cyclic, aromatic and/or aliphatic group or another B group which is the same or different. The material can be made by reacting at least one isocyanate and/or thioisocyanate with at least one amine, alcohol and/or thiol. Typically, the material is used first below its transition temperature, followed by increasing the temperature to around or above the transition temperature, carrying out a process step and subsequently decrease the temperature below the transition temperature.
- -
-
Page/Page column 11-12
(2008/12/08)
-