5701-00-8Relevant academic research and scientific papers
Practical metal-free C(sp3)-H functionalization: Construction of structurally diverse α-substituted N-benzyl and N-allyl carbamates
Xie, Zhiyu,Liu, Lei,Chen, Wenfang,Zheng, Hongbo,Xu, Qingqing,Yuan, Huiqing,Lou, Hongxiang
supporting information, p. 3904 - 3908 (2014/05/06)
Described is a practical and universal C-H functionalization of readily removable N-benzyl and N-allyl carbamates, with a wide range of nucleophiles at ambient temperature promoted by Ph3CClO4. The metal-free reaction has an excellent functional-group tolerance, and displays a broad scope with respect to both N-carbamates and nucleophile partners (a variety of organoboranes and C-H compounds). The synthetic utility in target- as well as diversity-oriented syntheses is demonstrated. Strategic play: A direct functionalization of the title carbamates with a wide range of nucleophiles has been developed. The reaction proceeds efficiently at low temperature using Ph3CClO4 as an oxidant. Sensitive functional groups are tolerated, thus allowing applications in natural product synthesis, the construction of chemical libraries, and the discovery of potential anticancer targets.
Synthesis of (+)-O-methylthalibrine by employing a stereocontrolled Bischler-Napieralski reaction and an electrochemically generated diaryl ether
Kawabata, Yuki,Naito, Yu,Saitoh, Tsuyoshi,Kawa, Kohei,Fuchigami, Toshio,Nishiyama, Shigeru
, p. 99 - 104 (2014/01/06)
An efficient electrochemical four-step route was developed for the preparation of diaryl ether derivatives by using halogenation and dehalogenation processes in addition to electrochemical phenolic oxidation and reduction reactions. The synthesis of (+)-O
Effect of isoquinoline alkaloids of different structural types on antiplatelet aggregation in vitro
Chia, Yi-Chen,Chang, Fang-Rong,Wu, Chin-Chung,Teng, Che-Ming,Chen, Keh-Shaw,Wu, Yang-Chang
, p. 1238 - 1241 (2007/10/03)
Forty-one isoquinoline alkaloids were tested for antiplatelet aggregation effects. Among them, (-)-discretamine (6), protopine (7), ochotensimine (18), O-methylarmepavinemethine (23), lindoldhamine (25), isotetrandrine (26), thalicarpine (27), papaverine (28), and D-(+)-N-norarmepavine (32) exhibited significant inhibitory activity towards adenosine 5′-diphosphate (ADP)-, arachidonic acid (AA)-, collagen-, and/or platelet-activating factor (PAF)-induced platelet aggregation. The results are discussed on the basis of structure-activity relationships. Georg Thieme Verlag KG Stuttgart.
A novel straightforward synthesis of enantiopure tetrahydroisoquinoline alkaloids
Pedrosa,Andres,Iglesias
, p. 243 - 250 (2007/10/03)
A novel, direct, and high-yielding stereoselective method for enantiopure 1-substituted tetrahydroisoquinolines (THIQ) is described. The successful approach, which creates the stereocenter during the formation of the THIQ nucleus is based on (i) formation of chiral 2,3-substituted perhydro-1,3-benzoxazines derived from (-)-8-aminomenthol, (ii) diastereoselective intramolecular ring opening of the N,O-acetal moiety by an arylmetal generated from the substituent at the nitrogen atom in the perhydrobenzoxazine ring, and (iii) removal of the chiral auxiliary appendage. The starting perhydrobenzoxazines are easily prepared from (-)-8-aminomenthol and two different aldehydes, and the intramolecular opening is stereospecific, leading to a single stereoisomer. The method allows the preparation of a wide variety of enantiopure 1-substituted THIQ, with different substituents at C-1, by changing the nature of the starting aldehydes.
Dehatrine, an antimalarial bisbenzylisoquinoline alkaloid from the Indonesian medicinal plant Beilschmiedia madang, isolated as a mixture of two rotational isomers
Kitagawa,Minagawa,Zhang,Hori,Doi,Inoue,Ishida,Kimura,Uji,Shibuya
, p. 997 - 999 (2007/10/02)
Through bioassay-guided separations of the chemical constituents of the Indonesian medicinal plant Beilschmiedia madang BL. A bisbenzylisoquinoline alkaloid was obtained as the major antimalarial principle. The physicochemical properties of the alkaloid were consistent with the proposed structure of dehatrine (1). However, the alkaloid isolated by us was shown to be a mixture of two rotational isomers. The X-ray crystallographic analysis of 1 has shown that two rotamers are incorporated in a single crystal 1:1 ratio. The complex NMR spectrum of 1 has also been defined as a mixture of two rotamers by extensive use of 2D (COSY and COLOC) techniques. Dehatrine (1) has been shown to significantly inhibit the growth of cultured Plasmodium falciparum K1 strain (chloroquine resistant) with similar activity to quinine.
