scholarly journals Development of a Simple Adjustable Zinc Acid/Base Hybrid Catalyst for C−C and C−O Bond‐Forming and C−C Bond‐Cleavage Reactions

2016 ◽  
Vol 11 (17) ◽  
pp. 2372-2376 ◽  
Author(s):  
Yasuhiro Yamashita ◽  
Kodai Minami ◽  
Yuki Saito ◽  
Shū Kobayashi
Keyword(s):  
Bond Cleavage ◽  
Hybrid Catalyst ◽  
Acid Base ◽  
Bond Forming ◽  
Cleavage Reactions

scholarly journals Transamidation of Amides and Amidation of Esters by Selective N–C(O)/O–C(O) Cleavage Mediated by Air- and Moisture-Stable Half-Sandwich Nickel(II)–NHC Complexes

Molecules ◽  
2021 ◽  
Vol 26 (1) ◽  
pp. 188
Author(s):  
Jonathan Buchspies ◽  
Md. Mahbubur Rahman ◽  
Michal Szostak
Keyword(s):  
Organic Synthesis ◽  
Bond Cleavage ◽  
Methyl Esters ◽  
Heterocyclic Carbenes ◽  
Amide Bond ◽  
Amide Bonds ◽  
Bond Forming ◽  
Cleavage Reactions ◽  
Metal Catalyzed ◽  
Half Sandwich

The formation of amide bonds represents one of the most fundamental processes in organic synthesis. Transition-metal-catalyzed activation of acyclic twisted amides has emerged as an increasingly powerful platform in synthesis. Herein, we report the transamidation of N-activated twisted amides by selective N–C(O) cleavage mediated by air- and moisture-stable half-sandwich Ni(II)–NHC (NHC = N-heterocyclic carbenes) complexes. We demonstrate that the readily available cyclopentadienyl complex, [CpNi(IPr)Cl] (IPr = 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene), promotes highly selective transamidation of the N–C(O) bond in twisted N-Boc amides with non-nucleophilic anilines. The reaction provides access to secondary anilides via the non-conventional amide bond-forming pathway. Furthermore, the amidation of activated phenolic and unactivated methyl esters mediated by [CpNi(IPr)Cl] is reported. This study sets the stage for the broad utilization of well-defined, air- and moisture-stable Ni(II)–NHC complexes in catalytic amide bond-forming protocols by unconventional C(acyl)–N and C(acyl)–O bond cleavage reactions.

scholarly journals Recent Advances in C–H Bond Functionalization with Ruthenium-Based Catalysts

Catalysts ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 173 ◽  
Author(s):  
Keisham Singh
Keyword(s):  
Transition Metals ◽  
Bond Cleavage ◽  
Rapid Development ◽  
Bond Functionalization ◽  
Bond Forming ◽  
The Past ◽  
Tremendous Progress ◽  
Specific Manner ◽  
Ruthenium Catalysis ◽  
Cleavage Reactions

The past decades have witnessed rapid development in organic synthesis via catalysis, particularly the reactions through C–H bond functionalization. Transition metals such as Pd, Rh and Ru constitute a crucial catalyst in these C–H bond functionalization reactions. This process is highly attractive not only because it saves reaction time and reduces waste,but also, more importantly, it allows the reaction to be performed in a highly region specific manner. Indeed, several organic compounds could be readily accessed via C–H bond functionalization with transition metals. In the recent past, tremendous progress has been made on C–H bond functionalization via ruthenium catalysis, including less expensive but more stable ruthenium(II) catalysts. The ruthenium-catalysed C–H bond functionalization, viz. arylation, alkenylation, annulation, oxygenation, and halogenation involving C–C, C–O, C–N, and C–X bond forming reactions, has been described and presented in numerous reviews. This review discusses the recent development of C–H bond functionalization with various ruthenium-based catalysts. The first section of the review presents arylation reactions covering arylation directed by N–Heteroaryl groups, oxidative arylation, dehydrative arylation and arylation involving decarboxylative and sp3-C–H bond functionalization. Subsequently, the ruthenium-catalysed alkenylation, alkylation, allylation including oxidative alkenylation and meta-selective C–H bond alkylation has been presented. Finally, the oxidative annulation of various arenes with alkynes involving C–H/O–H or C–H/N–H bond cleavage reactions has been discussed.

Hydrogenation-dehydrogenation and cleavage functions of hydrorefining catalysts studied by the reaction of tetrahydrothiophene

1986 ◽  
Vol 51 (12) ◽  
pp. 2770-2780 ◽  
Author(s):  
Alexandra Drahorádová ◽  
Miroslav Zdražil
Keyword(s):  
Activated Carbon ◽  
Catalyst Surface ◽  
Bond Cleavage ◽  
Unsaturated Hydrocarbons ◽  
Cleavage Reactions

The reaction of tetrahydrothiophene in a stream of nitrogen was used to study the relations between dehydrogenation and C-S cleavage reactions on sulphided Co-Mo/Al2O3 catalysts. The course of the reaction was compared for Co-Mo catalysts supported on alumina and activated carbon, for alumina alone as well as for a Pt/C catalyst. The effect of substitution of nitrogen for hydrogen, of the addition of water to the feed, of pre-sulphidation of catalysts and their deactivation by coking on the rate and selectivity of the reaction were also investigated. The results showed that hydrogenation-dehydrogenation and dehydrosulphurization activity of the sulphide catalysts have the same origin. Hydrogen accelerates dehydrosulphurization on the sulphide catalysts by removing sulphur and unsaturated hydrocarbons formed on catalyst surface by C-S bond cleavage reactions.

Reactions of 1,8-bis(diphenylphosphino)naphthalene with ruthenium cluster carbonyls: C–H and C–P bond cleavage reactions

2004 ◽  
Vol 357 (6) ◽  
pp. 1805-1812 ◽  
Author(s):  
Michael I. Bruce ◽  
Paul A. Humphrey ◽  
Sakir Okucu ◽  
Reinhard Schmutzler ◽  
Brian W. Skelton ◽  
...  
Keyword(s):  
Bond Cleavage ◽  
Ruthenium Cluster ◽  
Cleavage Reactions

Reactivity of Highly Lewis-Acidic Diborane(4) toward C≡N and N=N Bonds: Uncatalyzed Addition and N=N Bond-Cleavage Reactions

2018 ◽  
Vol 131 (1) ◽  
pp. 323-327 ◽  
Author(s):  
Yuhei Katsuma ◽  
Linlin Wu ◽  
Zhenyang Lin ◽  
Seiji Akiyama ◽  
Makoto Yamashita
Keyword(s):  
Bond Cleavage ◽  
Cleavage Reactions

Ultrasonically dispersed potassium in organic synthesis. Water-acceleration in reductive CS bond cleavage reactions

1991 ◽  
Vol 32 (29) ◽  
pp. 3551-3554 ◽  
Author(s):  
Ta-shue Chou ◽  
Shao-Hwa Hung ◽  
Man-Li Peng ◽  
Shwu-Jiaun Lee
Keyword(s):  
Organic Synthesis ◽  
Bond Cleavage ◽  
Cleavage Reactions

ChemInform Abstract: Oxygen Switch in Visible-Light Photoredox Catalysis: Radical Additions and Cyclizations and Unexpected C-C-Bond Cleavage Reactions.

ChemInform ◽  
2013 ◽  
Vol 44 (29) ◽  
pp. no-no
Author(s):  
Shaoqun Zhu ◽  
Arindam Das ◽  
Lan Bui ◽  
Hanjun Zhou ◽  
Dennis P. Curran ◽  
...  
Keyword(s):  
Visible Light ◽  
Bond Cleavage ◽  
Photoredox Catalysis ◽  
Cleavage Reactions
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