- ARISTOLACTAMS AND 4,5-DIOXOAPORPHINES FROM PIPER LONGUM
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Nine alkaloids were isolated from the cold ethanol extract of Piper longum roots, of which six known compounds were identified as cepharadione B, cepharadione A, cepharanone B, aristolactam AII, norcepharadione B, and 2-hydroxy-1-methoxy-4H-dibenzoquinoline-4,5(6H)-dione.The three new alkaloids were characterized as 10-amino-4-hydroxy-3-methoxyphenanthrene-1-carboxylic acid lactam , 10-amino-4-hydroxy-2,3-dimethoxyphenanthrene-1-carboxylic acid lactam and 2-hydroxy-1-methoxy-6-methyl-4H-dibenzoquinoline-4,5(6H)-dione .Key Word Index - Piper longum; Piperaceae; root alkaloids; aristolactams; dioxoaporphines; piperolactam A; piperolactam B; piperadione; NMR.
- Desai, Sanjay J.,Prabhu, Bharathi R.,Mulchandani, Newand B.
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- A simple, efficient route to the synthesis of dibenzocoumaranones and aristolactams
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We report the first synthesis of dibenzo[cdf]coumaranones that could be readily transformed into their nitrogen analogues, the aristolactams.
- Estevez,Carmen Villaverde,Estevez,Castedo
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- Phosphazene Superbase-Mediated Regio- and Stereoselective Iodoaminocyclization of 2-(1-Alkynyl)benzamides for the Synthesis of Isoindolin-1-ones
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Phosphazene superbase P4-t-Bu mediated iodoaminocyclization of 2-(1-alkynyl)benzamides is reported. The reaction works under ambient conditions and instantaneously results in the synthesis of isoindolin-1-ones in 65-97% yields, in a regio- and stereoselective manner. The exclusive formation of products with Z-geometry (across the exo C?C bond) has been confirmed through X-ray crystallography. The methodology also provides an easy access to aristolactams, an important class of natural products. This has been successfully demonstrated by synthesizing two aristolactam derivatives (including Cepharanone B).
- Mehta, Saurabh,Brahmchari, Dhirendra
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p. 5492 - 5503
(2019/05/10)
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- Pd(II)/Cu(II)-Catalyzed Regio- and Stereoselective Synthesis of (E)-3-Arylmethyleneisoindolin-1-ones Using Air as the Terminal Oxidant
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Regio- and stereoselective synthesis of (E)-3-arylmethyleneisoindolin-1-ones via Pd(II)/Cu(II)-catalyzed one-pot C-C/C-N bond forming sequence between amides and styrenes is reported. This method provides facile and rapid access to a diverse range of such compounds using readily available starting materials under mild aerobic conditions with good functional group tolerance and high selectivity and efficiency. Further elaboration of the products obtained from this process enabled very short and efficient syntheses of aristolactam and indoloisoquinolinone alkaloids.
- Youn, So Won,Ko, Tae Yun,Kim, Young Ho,Kim, Yun Ah
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supporting information
p. 7869 - 7874
(2019/01/14)
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- Heteroannulation enabled by a bimetallic Rh(III)/Ag(i) relay catalysis: Application in the total synthesis of aristolactam BII
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A redox-neutral bimetallic Rh(iii)/Ag(i) relay catalysis allowed the efficient construction of 3-alkylidene isoindolinones and 3-alkylidene isobenzofuranones. The Rh(iii) catalyst was responsible for the C-H monofluoroalkenylation reaction, whereas the Ag(i) salt was an activator for the follow-up cyclization. The methodology developed was applied as a key step in the rapid total synthesis of the natural product aristolactam BII.
- Ji, Wei-Wei,Lin,Li, Qingjiang,Wang, Honggen
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supporting information
p. 5665 - 5668
(2017/07/07)
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- Total synthesis of aristolactam alkaloids: Via synergistic C-H bond activation and dehydro-Diels-Alder reactions
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A concise total synthesis of aristolactam alkaloids by a synergistic combination of C-H bond activation and dehydro-Diels-Alder reactions is described. To achieve the synthesis two new synthetic methodologies, namely the oxidative cyclization of benzamides with vinyl sulfone leading to 3-methyleneisoindolin-1-ones via a ruthenium-catalyzed C-H bond activation, and a dehydro-Diels-Alder reaction followed by the fluoride ion mediated desulfonylation of 3-methyleneisoindolin-1-ones with benzynes, were developed. The method presented allows the opportunity for the construction of all the rings of aristolactams from easily available starting materials.
- Reddy, Mallu Chenna,Jeganmohan, Masilamani
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p. 4130 - 4135
(2017/07/11)
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- Iodine/water-mediated oxidation of o-alkynylaroyl compounds and application of the products of oxidation in the synthesis of nitrogen heterocycles
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A facile iodine/water-mediated oxidation of the triple bond of o-alkynylaroyl compounds to furnish tricarbonyl compounds is reported. The reaction proceeds through the formation of isochromenol intermediates by the assistance of the neighbouring aroyl gro
- Sakthivel, Karuppusamy,Srinivasan, Kannupal
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p. 3386 - 3396
(2013/06/27)
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- PHENANTHRENE LACTAM DERIVATIVES HAVING ANTICANCER ACTIVITY AND METHOD FOR THE PREPARATION THEREOF
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The present invention relates to a phenanthrene lactam derivative having anticanter activity, a method for the preparation thereof, and a pharmaceutical composition comprising same.
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Page/Page column 18
(2009/05/28)
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- Synthesis of aristolactam analogues and evaluation of their antitumor activity
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A series of natural aristolactams and their analogues have been prepared and evaluated for antitumor activity against human cancer cells, including multi-drug resistant cell lines. Naturally occurring aristolactams, such as aristolactam BII (cepharanone B
- Choi, Young Lok,Kim, Joa Kyum,Choi, Sang-Un,Min, Yong-Ki,Bae, Myung-Ae,Kim, Bum Tae,Heo, Jung-Nyoung
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experimental part
p. 3036 - 3040
(2010/02/28)
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- Total synthesis of aristolactams via a one-pot Suzuki-Miyaura coupling/aldol condensation cascade reaction
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(Chemical Equation Presented) A direct one-pot synthesis of phenanthrene lactams, which employs a Suzuki -Miyaura coupling/aldol condensation cascade reaction of isoindolin-1-one with 2-formylphenylboronic acid, has been developed. The approach is used to
- Kim, Joa Kyum,Kim, Young Ha,Nam, Ho Tae,Kim, Bum Tae,Heo, Jung-Nyoung
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supporting information; experimental part
p. 3543 - 3546
(2009/05/07)
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- A new approach to the synthesis of aristolactams. Total synthesis of cepharanone A and B
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An efficient, concise and tactically new synthesis of aristolactams is described. The key step is the aryne-mediated cyclization of an amino carbanion derived from a phosphorylated halobenzamide derivative. Horner reaction, radical cyclization and ultimate deprotection complete the synthesis of the phenanthrene lactam alkaloids. The viability of the strategy is further illustrated by the synthesis of cepharanone A and B.
- Couture, Axel,Deniau, Eric,Grandclaudon, Pierre,Lebrun, Stéphane
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p. 1475 - 1477
(2007/10/03)
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- Tributyltin(IV) hydride mediated free-radical syntheses of dehydrodibenzochromanones, dehydrodibenzocoumaranones and aristolactams
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We describe free radical cyclization of methyl bromophenylacetylphenylacetates to novel dehydrodibenzo[de,g]chromanones; oxidation of the latter compounds allowed the first total synthesis of dehydrodibenzo[cd,f]coumaranones, which are easily transformed
- Estevez, Juan C.,Villaverde, M. Carmen,Estevez, Ramon J.,Castedo, Luis
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p. 4075 - 4082
(2007/10/02)
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- STILBENE PHOTOCYCLIZATION. SYNTHESIS OF CEPHARANONE B
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The photocyclization of enamides of type 2 is investigated.Photochemical electrocyclization did not take place due to an ineffectiveness of overlapping of the hexatriene system.However, radical induced cyclization gave a satisfactory result.
- Castedo, Luis,Guitian, Enrique,Saa, Jose M.,Suau, Rafael
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p. 279 - 280
(2007/10/02)
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