142355-83-7Relevant articles and documents
A method for one-step synthesis of carboxylic acids with two extended carbon chains from olefins
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, (2020/10/12)
The invention relates to a method for one-step synthesis of carboxylic acid with two extended carbon chains from olefin, which comprises the following steps: under the protection of inert gas, sequentially adding an olefin substrate, a photocatalyst, a hydrogen atom transfer reagent, alpha-haloacetic acid, a reducing agent, a solvent and protonic acid into a reactor, and reacting at normal temperature under the irradiation of 25W blue light to obtain a reaction product; diluting, alkalizing, washing, acidifying and extracting the reaction product to obtain an organic phase; and finally, carrying out reduced pressure distillation and column chromatography on the organic phase to obtain a carboxylic acid product with two extended carbon chains; or carrying out reduced pressure distillation and column chromatography on the reaction product to obtain a carboxylic acid product with two extended carbon chains. The invention is simple to operate, direct synthesis conditions are mild, mutual conversion among various functional groups in the traditional carboxylic acid compound synthesis process is avoided, and the atom and step economy of the reaction is improved. Meanwhile, the method disclosed by the invention can also be applied to the simplified synthesis of the medicines cinacarbazide and tirofiban.
Metallaphotoredox-catalysed sp3-sp3 cross-coupling of carboxylic acids with alkyl halides
Johnston, Craig P.,Smith, Russell T.,Allmendinger, Simon,MacMillan, David W. C.
, p. 322 - 325 (2016/08/30)
In the past 50 years, cross-coupling reactions mediated by transition metals have changed the way in which complex organic molecules are synthesized. The predictable and chemoselective nature of these transformations has led to their widespread adoption across many areas of chemical research. However, the construction of a bond between two sp3-hybridized carbon atoms, a fundamental unit of organic chemistry, remains an important yet elusive objective for engineering cross-coupling reactions. In comparison to related procedures with sp2-hybridized species, the development of methods for sp3-sp3 bond formation via transition metal catalysis has been hampered historically by deleterious side-reactions, such as β-hydride elimination with palladium catalysis or the reluctance of alkyl halides to undergo oxidative addition. To address this issue, nickel-catalysed cross-coupling processes can be used to form sp3-sp3 bonds that utilize organometallic nucleophiles and alkyl electrophiles. In particular, the coupling of alkyl halides with pre-generated organozinc, Grignard and organoborane species has been used to furnish diverse molecular structures. However, the manipulations required to produce these activated structures is inefficient, leading to poor step-and atom-economies. Moreover, the operational difficulties associated with making and using these reactive coupling partners, and preserving them through a synthetic sequence, has hindered their widespread adoption. A generically useful sp3-sp3 coupling technology that uses bench-stable, native organic functional groups, without the need for pre-functionalization or substrate derivatization, would therefore be valuable. Here we demonstrate that the synergistic merger of photoredox and nickel catalysis enables the direct formation of sp3-sp3 bonds using only simple carboxylic acids and alkyl halides as the nucleophilic and electrophilic coupling partners, respectively. This metallaphotoredox protocol is suitable for many primary and secondary carboxylic acids. The merit of this coupling strategy is illustrated by the synthesis of the pharmaceutical tirofiban in four steps from commercially available starting materials.
Synthesis and biological evaluation of PEG-tirofiban conjugates
Desaubry, Laurent,Riche, Stephanie,Laeuffer, Patricia,Cazenave, Jean-Pierre
, p. 2028 - 2031 (2008/09/21)
We have conjugated tirofiban, an antagonist of the GPIIb/IIIa integrin receptor, to PEG, and shown that these polymers effectively inhibit platelet aggregation. This inhibition decreased with the size of the polymer. Our goal was to develop new cryoprotec
