7132-64-1Relevant articles and documents
Structures of nine oxygenated 4-methylene sterols from Hachijo marine sponge Theonella swinhoei
Sugo, Yumi,Inouye, Yoshinobu,Nakayama, Noboru
, p. 738 - 742 (1995)
Nine new sterols have been isolated from a marine sponge, Theonella swinhoei.Of these, seven sterols were found to be conicasterol derivatives oxygenated at carbon-7 and/or carbon-15.The other two were (24R)-7β,8β-epoxy-14α-methoxy-4-methylene-24-methylcholestan-3β-ol and (24R)-8,14-seco-8,14-dioxo-4-methylene-24-methylcholestan-3β-ol. - Keywords: marine sterol; 4-methylene sterol; conicasterol derivatives; Theonella swinhoei; marine sponge
Sterically hindered (pyridyl)benzamidine palladium(II) complexes: Syntheses, structural studies, and applications as catalysts in the methoxycarbonylation of olefins
Akiri, Saphan O.,Ojwach, Stephen O.
, (2021/09/09)
Reactions of ligands (E)-N′-(2,6-diisopropylphenyl)-N-(4-methylpyridin-2-yl)benzimidamide (L1), (E)-N′-(2,6-diisopropylphenyl)-N-(6-methylpyridin-2-yl)benzimidamide (L2), (E)-N′-(2,6-dimethylphenyl)-N-(6-methylpyridin-2-yl)benzimidamide (L3), (E)-N′-(2,6-dimethylphenyl)-N-(4-methylpyridin-2-yl)benzimidamide (L4), and (E)-N-(6-methylpyridin-2-yl)-N′-phenylbenzimidamide (L5) with [Pd(NCMe)2Cl2] furnished the corresponding palladium(II) precatalysts (Pd1–Pd5), in good yields. Molecular structures of Pd2 and Pd3 revealed that the ligands coordinate in a N^N bidentate mode to afford square planar compounds. Activation of the palladium(II) complexes with para-tolyl sulfonic acid (PTSA) afforded active catalysts in the methoxycarbonylation of a number of alkene. The resultant catalytic activities were controlled by the both the complex structure and alkene substrate. While aliphatic substrates favored the formation of linear esters (>70%), styrene substrate resulted in the formation of predominantly branched esters of up to 91%.
Visible light-driven Giese reaction with alkyl tosylates catalysed by nucleophilic cobalt
Komeyama, Kimihiro,Michiyuki, Takuya,Teshima, Yoshikazu,Osaka, Itaru
, p. 3539 - 3546 (2021/02/03)
The scope of the Giese reaction is expanded using readily available alkyl tosylates as substrates and nucleophilic cobalt(i) catalysts under visible-light irradiation. The reaction proceeds preferentially with less bulky primary alkyl tosylates. This unique reactivity enables the regio-selective Giese reaction of polyol derivatives.
Dammarane triterpenoids from Carnauba, Copernicia prunifera (Miller) H. E. Moore (Arecaceae), wax
De Almeida, Buana C.,Araújo, Bruno Q.,Barros, Elcio D. S.,Freitas, Samya D. L.,Maciel, Dayany S. A.,Ferreira, Ari J. S.,Guadagnin, Rafael C.,Vieira, Gerardo M.,Lago, Jo?o H. G.,Chaves, Mariana H.
, p. 1371 - 1376 (2017/07/13)
Phytochemical investigation from carnauba (Copernicia prunifera) wax led to the identification of sixteen dammarane–type triterpenes, including thirteen new characterized as: (24R*)-methyldammara-20,25-dien-3α-ol and a mixture of alkyl (24R*)-methyldammar-25-en-20-ol-3β-carboxylates, together with three previously described triterpenes: carnaubadiol, (24R*)-methyldammara-20,25-dien-3β-ol and (24R*)-24-methyldammara-20,25-dien-3-one. Moreover, four fatty alcohols (eicosanol, docosanol, tetracosanol and hexacosanol) as well as four sterols (cholesterol, campesterol, stigmasterol, and sitosterol) were also obtained. These compounds were isolated using classical chromatographic methods and their structures were determined by spectroscopic and chemical methods.