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981.
982.
983.
Sohei Ueki Takayuki Ishida Takashi Nogami Kwang-Yong Choi Hiroyuki Nojiri 《Chemical physics letters》2007,440(4-6):263-267
A centrosymmetric rectangular complex [Dy4Cu] was prepared from dysprosium(III) 1,1,1,5,5,5-hexafluoropentane-2,4-dionate and copper(II) dimethylglyoximate. From magnetic studies, the Dy magnetic moments are all aligned parallel at the ground state via antiferromagnetic superexchange interaction with the central Cu spin. In pulsed-field magnetization measurements at 0.5 K, complex [Dy4Cu] exhibited magnetization steps with hysteresis, which is typical of a single-molecule magnet. This behavior is explained in terms of a simple Ising model together with well-defined Dy–Cu exchange coupling (−0.64 K). 相似文献
984.
A thirteen-step total synthesis of (±)-saframycin A from a tricyclic lactam intermediate is described. The key step of this total synthesis is the stereocontrolled construction of a pentacyclic saframycin framework via a modified Pictet-Spengler type cyclization generating a bis-carboxylic acid ester derivative, followed by decarboxylation. The cytotoxicity profiles are also presented. 相似文献
985.
986.
Kazuma Matsunaga Kazuhiko Takatori Hiroshi Kogen Naoki Saito 《Tetrahedron letters》2018,59(43):3872-3875
A synthetic route to 6,6-dimethyltricyclo[5.4.0.02,8]undecane-2,9-diol, a key precursor to (ent-)longipinane-type sesquiterpenoids, is described. This unique core common to (ent-)longipinanes was constructed using two types of intramolecular radical cyclization reactions, namely, intramolecular coupling of an acid chloride and an alkyl iodide mediated by SmI2, TBAI and HMPA, and the coupling of a ketone and an epoxide mediated by Cp2TiI2 and SmI2. 相似文献
987.
Enantioselective Denitrogenative Annulation of 1H‐Tetrazoles with Styrenes Catalyzed by Rhodium 下载免费PDF全文
Takayuki Nakamuro Kohei Hagiwara Dr. Tomoya Miura Prof. Dr. Masahiro Murakami 《Angewandte Chemie (International ed. in English)》2018,57(19):5497-5500
Sulfonylation of 1H‐tetrazoles with triflic anhydride in the presence of chiral rhodium(II) carboxylate dimers causes denitrogenation to generate α‐azo rhodium(II) carbenoid species as new types of donor/acceptor carbenoids, which then readily react with styrenes to afford 3,5‐diaryl‐2‐pyrazolines with a high degree of enantioselectivity. 相似文献
988.
Dr. Masahito Yoshida Dr. Koya Saito Dr. Hikaru Kato Prof. Dr. Sachiko Tsukamoto Prof. Dr. Takayuki Doi 《Angewandte Chemie (International ed. in English)》2018,57(18):5147-5150
The total synthesis of siladenoserinol A, an inhibitor of the p53–Hdm2 interaction, has been achieved. AuCl3‐catalyzed hydroalkoxylation of an alkynoate derivative smoothly and regioselectively proceeded to afford a bicycloketal in excellent yield. A glycerophosphocholine moiety was successfully introduced through the Horner–Wadsworth–Emmons reaction using an originally developed phosphonoacetate derivative. Finally, removal of the acid‐labile protecting groups, followed by regioselective sulfamate formation of the serinol moiety afforded the desired siladenoserinol A, and benzoyl and desulfamated analogues were also successfully synthesized. Biological evaluation showed that the sulfamate is essential for biological activity, and modification of the acyl group on the bicycloketal can improve the inhibitory activity against the p53–Hdm2 interaction. 相似文献
989.
990.