82104-74-3Relevant articles and documents
Visible Light-Promoted Magnesium, Iron, and Nickel Catalysis Enabling C(sp3)-H Lactonization of 2-Alkylbenzoic Acids
Li, Sasa,Su, Mincong,Sun, Jie,Hu, Kunjun,Jin, Jian
supporting information, p. 5842 - 5847 (2021/07/31)
A mild and practical C(sp3)-H lactonization protocol has been achieved by merging photocatalysis and magnesium (iron, nickel) catalysis. A diverse range of 2-alkylbenzoic acids with a variety of substitution patterns could be transformed into the corresponding phthalide products. Based on the mechanistic experimentation and reported prior studies, a possible mechanism for the benzylic oxidative lactonization reaction was proposed with the hypothetic photoactive ternary complex formed between the 2-alkylbenzoic acid substrate, magnesium ion, and bromate anion.
Nickel-Catalyzed Cyanation of Aryl Halides and Hydrocyanation of Alkynes via C-CN Bond Cleavage and Cyano Transfer
Chen, Hui,Sun, Shuhao,Liu, Yahu A.,Liao, Xuebin
, p. 1397 - 1405 (2020/02/04)
We report nickel-catalyzed cyanation and hydrocyanation methods to prepare aryl nitriles and vinyl nitriles from aryl halides and alkynes, respectively. Using inexpensive and nontoxic 4-cyanopyridine N-oxide as the cyano shuttle, the methods provide an efficient approach to prepare aryl cyanides and vinyl nitriles under mild and operationally simple reaction conditions with a broad range of functional group tolerances. In hydrocyanation of alkynes, the method demonstrated good regioselectivity, producing predominantly E- or Z-alkenyl nitriles in a controlled manner and exclusively Markovnikov vinyl nitriles when internal diaryl alkynes and terminal alkynes were applied as the substrates, respectively. The preliminary mechanistic investigation indicated that the C-CN bond cleavage process is promoted by oxidative addition to the nickel(I) complex in the cyanation of aryl halides, and further studies via a series of deuterium exchange experiments indicated that water serves as the hydrogen source for the hydrocyanation of alkynes.
Ni-Catalyzed Reductive Cyanation of Aryl Halides and Phenol Derivatives via Transnitrilation
Mills, L. Reginald,Graham, Joshua M.,Patel, Purvish,Rousseaux, Sophie A. L.
supporting information, p. 19257 - 19262 (2019/12/02)
Herein, we report a Ni-catalyzed reductive coupling for the synthesis of benzonitriles from aryl (pseudo)halides and an electrophilic cyanating reagent, 2-methyl-2-phenyl malononitrile (MPMN). MPMN is a bench-stable, carbon-bound electrophilic CN reagent that does not release cyanide under the reaction conditions. A variety of medicinally relevant benzonitriles can be made in good yields. Addition of NaBr to the reaction mixture allows for the use of more challenging aryl electrophiles such as aryl chlorides, tosylates, and triflates. Mechanistic investigations suggest that NaBr plays a role in facilitating oxidative addition with these substrates.
Ex situ generation of stoichiometric HCN and its application in the Pd-catalysed cyanation of aryl bromides: Evidence for a transmetallation step between two oxidative addition Pd-complexes
Kristensen, Steffan K.,Eikeland, Espen Z.,Taarning, Esben,Lindhardt, Anders T.,Skrydstrup, Troels
, p. 8094 - 8105 (2017/11/27)
A protocol for the Pd-catalysed cyanation of aryl bromides using near stoichiometric and gaseous hydrogen cyanide is reported for the first time. A two-chamber reactor was adopted for the safe liberation of ex situ generated HCN in a closed environment, which proved highly efficient in the Ni-catalysed hydrocyanation as the test reaction. Subsequently, this setup was exploited for converting a range of aryl and heteroaryl bromides (28 examples) directly into the corresponding benzonitriles in high yields, without the need for cyanide salts. Cyanation was achieved employing the Pd(0) precatalyst, P(tBu)3-Pd-G3 and a weak base, potassium acetate, in a dioxane-water solvent mixture. The methodology was also suitable for the synthesis of 13C-labelled benzonitriles with ex situ generated 13C-hydrogen cyanide. Stoichiometric studies with the metal complexes were undertaken to delineate the mechanism for this catalytic transformation. Treatment of Pd(P(tBu)3)2 with H13CN in THF provided two Pd-hydride complexes, (P(tBu)3)2Pd(H)(13CN), and [(P(tBu)3)Pd(H)]2Pd(13CN)4, both of which were isolated and characterised by NMR spectroscopy and X-ray crystal structure analysis. When the same reaction was performed in a THF : water mixture in the presence of KOAc, only (P(tBu)3)2Pd(H)(13CN) was formed. Subjection of this cyano hydride metal complex with the oxidative addition complex (P(tBu)3)Pd(Ph)(Br) in a 1 : 1 ratio in THF led to a transmetallation step with the formation of (P(tBu)3)2Pd(H)(Br) and 13C-benzonitrile from a reductive elimination step. These experiments suggest the possibility of a catalytic cycle involving initially the formation of two Pd(ii)-species from the oxidative addition of LnPd(0) into HCN and an aryl bromide followed by a transmetallation step to LnPd(Ar)(CN) and LnPd(H)(Br), which both reductively eliminate, the latter in the presence of KOAc, to generate the benzonitrile and LnPd(0).
Facile organocatalytic domino oxidation of diols to lactones by in situ-generated TetMe-IBX
Jhulki, Samik,Seth, Saona,Mondal, Manas,Moorthy, Jarugu Narasimha
, p. 2286 - 2293 (2014/03/21)
The domino oxidation of diols to lactones is an important transformation, and catalytic protocols that allow this conversion smoothly are scarce. Capitalizing on the established reactivity of tetramethyl-IBX (TetMe-IBX) and its in situ generation in the presence of a co-oxidant, such as oxone, we have shown that a variety of diols can be converted to the corresponding lactones in respectable yields by employing the precursor of TetMe-IBX, namely, tetramethyl-o-iodobenzoic acid (TetMe-IA), as a catalyst in 5 mol % in the presence of 2 equiv of oxone.
Process for the preparation of 5-cyanophthalide starting from 5-carboxyphthalide
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Page/Page column 4-5, (2008/06/13)
A new process is clescribed for obtaining 5-cyanophthalide, which is an intermediate used for the synthesis of citalopram and its active enantiomer S(+) citalopram, both of which are known active ingredients commonly used for treating depression. The process starts from 5-carboxyphthalide which is converted into the corresponding acylochloride. The latter is reacted with hydroxylamine to give the corresponding hydroxamyl phthalide which is subsequently subjected to a dehydration reaction to give 5-cyanophthalide.
AN IMPROVED PROCESS FOR THE PREPARATION OF 5-CYANOPHTHALIDE
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Page/Page column 7-8, (2008/06/13)
The invention disclosed an improved process for the preparation of 5-cyanophthalide which comprises reacting 5-carboxyphthalide with ammonium carbonate in the presence of ethyl polyphospate with or without a solvent and isolating the 5-cyanophthalide formed by conventional methods .
METHOD FOR THE PREPARATION OF 5-CYANOPHTHALIDE
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, (2008/06/13)
A method for the preparation of 5-cyanophthalide comprising treatment of a compound of formula IV wherein X is O or S; R1-R2 are each independently selected from hydrogen and C1-6 alkyl, or R1 and R2 together form a C2-5 alkylene chain thereby forming a spiro-ring; R3 is selected from hydrogen and C1-6 alkyl, R4 is selected from hydrogen, C1-6 alkyl, a carboxy group or a precursor group therefore, or R3 and R4 together form a C2-5 alkylene chain thereby forming a spiro-ring; with a dehydration agent or alternatively where X is S, thermally cleavage of the thiazoline ring or treatment with a radical initiator, such as peroxide or with light, to form 5-cyanophthalide, which is an important intermediate used in the preparation of the antidepressant drug citalopram.
WATER-SOLUBLE TRIAZOLE FUNGICIDE
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Page/Page column 113, (2010/02/07)
A triazole compound of the general formula (I) or a pharmacologically acceptable salt thereof: [wherein,X represents a group of formula X-OH which has antifungal activity,L represents a -(adjacently substituted C6-C10 aryl)-CH2-group and the like, andR represents a -P(=O) (OH)2 group and the like.
Method for the preparation of 5-cyanophthalide
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, (2008/06/13)
A method for the preparation of 5-cyanophthalide in which 5-carboxyphthalide is converted to the corresponding amide of Formula (IV) in which R is hydrogen or C1-6 alkyl, which is then reacted with a dehydrating agent thereby obtaining 5-cyanophthalide. The conversion of 5-carboxyphthalide to the corresponding amide of Formula (IV) may be carried out via the corresponding C1-6 alkyl or phenyl ester or the acid chloride, which is converted to the amide of Formula (IV) by amidation with ammonia or a C1-6 alkylamine. By the process 5-cyanophthalide, an important intermediate used in the preparation of the antidepressant citalopram, is prepared in high yields by a convenient, cost effective procedure.
