Brønsted acid-mediated ring-opening reactions of methylenecyclopropanes: a dramatic counter ion effect

We report herein two different ring-opening patterns of methylenecyclopropanes (MCPs) in the presence of two Brønsted acids heptadecafluorooctane-1-sulfonic acid (C₈F₁₇SO₃H) and toluene p-sulfonic acid (TsOH) under mild conditions: (a) the ring-opening of MCPs by H₂O and subsequent etherification give the corresponding homoallylic ethers in the presence of heptadecafluorooctane-1-sulfonic acid; (b) the direct ring-opening of MCPs by the Brønsted acid gives the corresponding homoallylic alcohol derivatives in the presence of toluene p-sulfonic acid.     

Diversity-oriented TsOH catalysis-enabled construction of tanshinone-substituted bis(indolyl/pyrrolyl)methanes and their biological evaluation for anticancer activities

We have developed an efficient and straightforward methodology for the synthesis of novel tanshinone-substituted bis(indolyl/pyrrolyl)methane scaffolds 3 through TsOH catalysis-enabled addition of indoles or pyrroles 1 with tanshinones 2 based on molecular hybridization strategy. Products were smoothly obtained in good yields (up to 81% yield). This protocol also represents the first construction of tanshinone skeleton-fused bis(indolyl/pyrrolyl)methane scaffolds, thus leading to new knowledge in the fields of both molecular complexity and diversity-oriented synthesis and the lead compound discovery. Furthermore, their biological activities against human leukemia cells K562, human prostate cancer cells PC-3, and human lung cancer cells A549 have been preliminarily demonstrated by in vitro assays. The results demonstrated that most of these compounds 3 obtained by this protocol showed comparable activity to the positive control of cisplatin.     

A Facile Synthesis of Benzo[h]quinolines via Silica‐TsOH‐P2O5 Promoted Condensation of 1‐Naphthylamines with 1,3‐Diketones under Solvent Free Conditions

A facile synthesis of benzo[h ]quinolines has been developed via improved Combes reaction. A combination of silica gel, p ‐toluenesulfonic acid and phosphorus pentoxide was utilized to promote the condensation of 1‐naphthylamines with 1,3‐diketones under solvent free conditions. In this case, silica gel was used as reaction media, p ‐toluenesulfonic acid and phosphorus pentoxide were acted as catalyst and dehydrating agent, respectively.     

One—pot Synthesis of 3,4—dihydropyrimidin—2（1H）—one Using TsOH as a Catalyst under Microwave Irradiation

A series of Biginelli compounds was synthesized using TsOH as a catalyst under microwave irradiation.This simple method provided the title compounds in 86%-98% yields by the reaction of aromatic aldehydes with 1,3-carbonyl compound and urea.The structure of 40 was determined by single crystal Xray diffraction analysis.     

3-乙基-2-丙基喹啉衍生物的合成工艺研究

以芳胺和正丁醛为原料,对甲基苯磺酸(TsOH)为促进剂,采用"一锅法"合成了3-乙基-2-丙基喹啉衍生物,系统地考察了原料比例、溶剂以及芳胺上取代基对反应的影响,比较了不同的质子酸促进剂对喹啉衍生物产率以及选择性的影响,并对产物进行了核磁共振表征.实验结果表明当用对甲基苯磺酸(TsOH)为促进剂时,3乙基-2-丙基喹啉收率可达到59%,同时生成40%N-丁基苯胺;磷钼酸、浓硫酸也可以选择性地得到喹啉衍生物,但收率较低,分别只有28%和24%.同时,考察了苯胺环上取代基对喹啉收率的影响,当苯环上有供电子基时,有利于喹啉的生成,而吸电子基则不利于喹啉的生成.并推测了反应机理.     

对甲苯磺酸与碘协同催化合成月桂酸甲酯

以甲醇(1)和月桂酸(2)为原料,碘和对甲苯磺酸协同催化合成了月桂酸甲酯(3),其结构经IR确证。考察了催化剂、反应时间、反应温度和物料比r[n(1)∶n(2)]对3产率的影响。结果表明:在最优反应条件(2 10mmol,r=15∶1,3 mol%TsOH,6 mol%I2,于60℃反应90 min)下,3产率93.5%。     

Synthesis under Microwave Irradiation and Crystal Structure of 4-（3,4-Methylenedioxylphenyl）-6-methyl- 5-ethoxycaronyl-3,4-dihydropyrimidin-2（H）-one

1 INTRODUCTION Since Biginelli firstly reported the synthesis of 3,4-dihydropyrimidin-2(1H)-ones in 1893, this com- pound has been found to emerge as calcium channel blockers, antihypersive agents and a-antagonists[1]. Consequently, this Biginelli reacti…