3,5-Di-tert-butyl-1,2-benzoquinone Cleaves a CC-bond in Vicinal Aminobenzyl Alcohols

1994 ◽  
Vol 59 (1) ◽  
pp. 227-230 ◽  
Author(s):  
Václav Horák ◽  
Yonco Mermersky ◽  
Dalal B. Guirguis
Keyword(s):  
Bond Cleavage ◽  
Tert Butyl ◽  
Mild Conditions ◽  
High Yields

Two vicinal aminobenzyl alcohols, L-threo-1-(4-methylthiophenyl)-2-amino-1,3-propanediol (IIa) and 1-phenyl-2-amino-1,3-propanediol (IIb), underwent, under mild conditions, CC-bond cleavage with 3,5-di-tert-butyl-1,2-benzoquinone (I) producing in high yields 4-methylthiobenzaldehyde (Va) and benzaldehyde (Vb), respectively, and 2-hydroxymethyl-4,6-di-tert-butylbenzoxazole (VII). Ethanolamine (VIII) under identical conditions produced benzoxazole VII. The reported reaction is a second case in which quinone I mimics reactions of pyridoxal.

scholarly journals Decarbonylation through Aldehydic C–H Bond Cleavage by a Cationic Iridium Catalyst

Synlett ◽  
2019 ◽  
Vol 30 (08) ◽  
pp. 972-976 ◽  
Author(s):  
Tomohiko Shirai ◽  
Kazuki Sugimoto ◽  
Masaya Iwasaki ◽  
Ryuki Sumida ◽  
Harunori Fujita ◽  
...  
Keyword(s):  
Bond Cleavage ◽  
Catalyst System ◽  
Mild Conditions ◽  
Iridium Catalyst ◽  
Reaction Proceeds ◽  
High Yields

We report the decarbonylation of aldehydes through an aldehydic C–H bond cleavage catalyzed by a cationic iridium/bisphosphine catalyst. The reaction proceeds under relatively mild conditions to give the corresponding hydrocarbon products in moderate to high yields. In addition, this cationic iridium catalyst system can be applied to an asymmetric hydroacylation of ketones.

Synthesis and use of benzyl tert-butyl iminodicarbonate, a versatile reagent for the preparation of amines

1988 ◽  
Vol 53 (11) ◽  
pp. 2778-2786 ◽  
Author(s):  
Leif Grehn ◽  
Ulf Ragnarsson
Keyword(s):  
Benzyl Alcohol ◽  
Sodium Salt ◽  
Title Compound ◽  
Protecting Groups ◽  
Efficient Synthesis ◽  
Tert Butyl ◽  
Mild Conditions ◽  
High Yields ◽  
Versatile Reagent

An efficient synthesis of benzyl tert-butyl iminodicarbonate (IV), starting from benzoyl isocyanate, is reported. Reaction of the isocyanate with benzyl alcohol gave benzyl N-benzoylcarbamate (II) which on exhaustive tert-butoxycarbonylation via the non-isolated triacyl amine III, after aminolysis, provided the title compound. The sodium salt V was alkylated with various halides under Gabriel conditions to give in high yields the corresponding benzyloxycarbonyl tert-butoxycarbonyl diprotected amines. Similarly, compound IV was alkylated with alcohols under Mitsunobu conditions to give some additional amines of this type, from which the protecting groups can be removed selectively under mild conditions.

Samarium diiodide mediated regeneration of 1,2-benzene diamine and preparation of benzimidazolin-2-ones from 2,1,3-benzothiadiazoles

2005 ◽  
Vol 2005 (1) ◽  
pp. 21-22 ◽  
Author(s):  
Xuesen Fan ◽  
Xinying Zhang ◽  
Yongmin Zhang
Keyword(s):  
Bond Cleavage ◽  
Samarium Diiodide ◽  
Mild Conditions ◽  
High Yields

On treatment with SmI2 in THF and in the presence of methanol, 2,1,3-benzothiadiazoles underwent reductive N–S bond cleavage leading to 1,2-benzenediamines in high yields. Without methanol but in the presence of triphosgene, benzimidazolin-2-ones were obtained in moderate yields under mild conditions.

Palladium-catalyzed Suzuki cross-couplings of N′-mesyl arylhydrazines via C–N bond cleavage

RSC Advances ◽  
2014 ◽  
Vol 4 (49) ◽  
pp. 25576-25579 ◽  
Author(s):  
He-Ping Zhou ◽  
Jin-Biao Liu ◽  
Jian-Jun Yuan ◽  
Yi-Yuan Peng
Keyword(s):  
Boronic Acid ◽  
Bond Cleavage ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Mild Conditions ◽  
Cross Coupling Reaction ◽  
Palladium Catalyzed ◽  
High Yields ◽  
Aryl Boronic Acid ◽  
Biaryl Compounds

An efficient palladium-catalyzed Suzuki cross-coupling reaction of N′-mesyl arylhydrazine with aryl boronic acid is described, which affords the corresponding biaryl compounds in high yields. This transformation proceeds through C–N bond cleavage under mild conditions.

scholarly journals Enantioselective cyanation via radical-mediated C–C single bond cleavage for synthesis of chiral dinitriles

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Tao Wang ◽  
Yi-Ning Wang ◽  
Rui Wang ◽  
Bo-Chao Zhang ◽  
Chi Yang ◽  
...  
Keyword(s):  
Ring Opening ◽  
Bond Cleavage ◽  
Catalyst Loading ◽  
Small Ring ◽  
Single Bond ◽  
Asymmetric Transformations ◽  
Mild Conditions ◽  
Ring Opening Reaction ◽  
High Yields ◽  
Low Catalyst Loading

AbstractRing-opening reaction via selective cleavage of C–C bond is known as a powerful strategy for construction of complex molecules. Complementary to the ionic process focusing on mostly small ring systems, radical-mediated C–C bond cleavage offers a solution for further diverse enantioselective functionalization benefited from its mild conditions, whereas such asymmetric transformations are still limited to three-membered rings so far. Herein, we describe radical-mediated ring-opening and enantioselective cyanation of four- and five-membered cycloketone oxime esters to access chiral 1,5- and 1,6-dinitriles. Employment of dual photoredox/copper catalysis is essential for the asymmetric ring-opening cyanation of cyclopentanone oxime esters. Both reactions proceed under mild conditions giving chiral dinitriles in high yields and enantioselectivity with low catalyst loading and broad substrate scope. The products dinitriles can be converted to valuable optically active diamides and diamines. Mechanistic studies indicate that the benzylic radical generated via C–C single bond cleavage is involved in the catalytic cycle.

Electron Donation by Low-Crystalline Ba-La-Ce Oxygen-Deficient Composite Oxide Accumulating on Ru Nanoparticles for Ammonia Synthesis under Mild Conditions

2019 ◽  
Author(s):  
Katsutoshi Sato ◽  
Shin-ichiro Miyahara ◽  
Yuta Ogura ◽  
Kotoko Tsujimaru ◽  
Yuichiro Wada ◽  
...  
Keyword(s):  
Ammonia Synthesis ◽  
Bond Cleavage ◽  
Synthesis Process ◽  
Strong Electron ◽  
Mild Conditions ◽  
Ru Nanoparticles ◽  
Rate Determining Step ◽  
Highly Active ◽  
Composite Oxides ◽  
Low Crystalline

<p>To mitigate global problems related to energy and global warming, it is helpful to develop an ammonia synthesis process using catalysts that are highly active under mild conditions. Here we show that the ammonia synthesis activity of Ru/Ba/LaCeO<i><sub>x</sub></i> pre-reduced at 700 °C is the highest reported among oxide-supported Ru catalysts. Our results indicate that low crystalline oxygen-deficient composite oxides, which include Ba<sup>2+</sup>, Ce<sup>3+</sup> and La<sup>3+</sup>, with strong electron-donating ability, accumulate on Ru particles and thus promote N≡N bond cleavage, which is the rate determining step for ammonia synthesis.</p>

Electron Donation by Low-Crystalline Ba-La-Ce Oxygen-Deficient Composite Oxide Accumulating on Ru Nanoparticles for Ammonia Synthesis under Mild Conditions

2019 ◽  
Author(s):  
Katsutoshi Sato ◽  
Shin-ichiro Miyahara ◽  
Yuta Ogura ◽  
Kotoko Tsujimaru ◽  
Yuichiro Wada ◽  
...  
Keyword(s):  
Ammonia Synthesis ◽  
Bond Cleavage ◽  
Synthesis Process ◽  
Strong Electron ◽  
Mild Conditions ◽  
Ru Nanoparticles ◽  
Rate Determining Step ◽  
Highly Active ◽  
Composite Oxides ◽  
Low Crystalline

<p>To mitigate global problems related to energy and global warming, it is helpful to develop an ammonia synthesis process using catalysts that are highly active under mild conditions. Here we show that the ammonia synthesis activity of Ru/Ba/LaCeO<i><sub>x</sub></i> pre-reduced at 700 °C is the highest reported among oxide-supported Ru catalysts. Our results indicate that low crystalline oxygen-deficient composite oxides, which include Ba<sup>2+</sup>, Ce<sup>3+</sup> and La<sup>3+</sup>, with strong electron-donating ability, accumulate on Ru particles and thus promote N≡N bond cleavage, which is the rate determining step for ammonia synthesis.</p>

scholarly journals Electrochemical multicomponent synthesis of 4-selanylpyrazoles under catalyst- and chemical-oxidant-free conditions

2021 ◽  
Author(s):  
Yan Wu ◽  
Jin-Yang Chen ◽  
Jing Ning ◽  
Xue Jiang ◽  
Jie Deng ◽  
...  
Keyword(s):  
Multicomponent Reaction ◽  
Raw Materials ◽  
Multicomponent Synthesis ◽  
Mild Conditions ◽  
Simple Protocol ◽  
High Yields

An electrochemical multicomponent reaction was established under catalyst-, chemical-oxidant-free and mild conditions, which provides an eco-friendly and simple protocol for constructing 4-selanylpyrazoles from easily available raw materials with high yields.

scholarly journals A New and Efficient One-pot Synthesis of Trialkyl 6-tert-Butylamino-2H-pyran-2-one-3,4,5-tricarboxylates

1999 ◽  
Vol 23 (6) ◽  
pp. 368-369
Author(s):  
Issa Yavari ◽  
Abbas Ali Esmaili ◽  
Sakineh Asghari ◽  
Hamid Reza Bijanzadeh
Keyword(s):  
One Pot ◽  
Tert Butyl ◽  
Dialkyl Acetylenedicarboxylates ◽  
One Pot Synthesis ◽  
High Yields

The highly reactive 1:1 intermediate produced in the reaction between tert-butyl isocyanide and dialkyl acetylenedicarboxylates is trapped by dialkyl 2-bromomalonates to yield the title compounds in fairly high yields.

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