Erratum to “Two novel nortriterpenes from the roots of Phlomis umbrosa” [Chin. Chem. Lett. 19 (2008) 1228–1230]

Two novel 28-noroleanane-derived spirocyclic triterpenoids with unusual skeleton structures, phlomishexaol C (1), phlomishexaol D (2) were isolated from the roots of Phlomis umbrosa. Their structures were elucidated by spectroscopic methods, including 1D, 2D nuclear magnetic resonance (NMR), high-resolution mass spectrometry (HR-MS).     

Fe（HSO4）3： An efficient,heterogeneous and reusable catalyst for the synthesis of 14-aryl- or alkyl- 14H-dibenzo[a,j]xanthenes

Fe（HSO4）3 has been used as an efficient and recyclable catalyst for the one-pot synthesis of 14-aryl- or alkyl-14Hdibenzo[aj]xanthene derivatives by the reaction of 2-naphtol and aldehydes. Different types of aromatic and aliphatic aldehydes are used in the reaction and in all cases the products were obtained in good to excellent yields.     

An efficient, high yielding, and eco-friendly method for the synthesis of 14-aryl- or 14-alkyl-14H-dibenzo[a,j]xanthenes using polyvinylsulfonic acid as a recyclable Br?nsted acid catalyst

Abstract  

Aryl or alkyl-14H-dibenzo[a,j]xanthene derivatives were synthesized efficiently by the reaction of 2-naphthol and aromatic or aliphatic aldehydes in the presence of polyvinylsulfonic acid (PVSA) as a reusable Br?nsted acid catalyst under aqueous conditions at 90 °C. This reaction was studied under different conditions, and several solvents were examined. In terms of reaction yield and time, water was found to be the optimum solvent. The catalytic performance of PVSA was then compared with various acidic catalysts under optimized reaction conditions. The catalyst is well characterized using IR and DSC techniques.     

Erratum on “Reductive immobilization of Re(Ⅶ) by graphene modified nanoscale zero-valent iron particles using a plasma technique” [Sci.China Chem.,2016,59:150–158]

We regret that our article Reductive immobilization of Re(Ⅶ) by graphene modified nanoscale zero-valent iron particles using a plasma technique(Sci. China Chem., 2016, 59:150–158)[1] contained errors. The corrections in an erratum do not change or affect the result or conclusion of the paper.