A Quick, Clean and Green Synthesis of Methylenedioxyprecocene and other Chromenes over Basic Montmorillonite K10 Clay
作者:Matthew R. Dintzner、Thomas W. Lyons、Michael H. Akroush、Paul Wucka、Adam T. Rzepka
DOI:10.1055/s-2005-863738
日期:——
The microwave-assisted, clay-catalyzed condensation of sesamol and other phenols with 3-methyl-2-butenal to give methylenedioxyprecocene 3 and other chromenes, is described.
NITRILES AND MEDICINAL COMPOSITIONS CONTAINING THE SAME AS THE ACTIVE INGREDIENT
申请人:ONO PHARMACEUTICAL CO., LTD.
公开号:EP1724264A1
公开(公告)日:2006-11-22
The present invention relates to a compound of formula (I)
wherein Y and Z each is independently N or C; ring A is a carbocyclic group or a heterocyclic group; ring B is a heterocyclic group containing at least one nitrogen atom; R is a hydrogen atom, a substituent, etc,; n is 0, or an integer of from 1 to 10, a salt thereof, a solvate thereof, or an N-oxide thereof, or a prodrug thereof. The compound of formula (I), a salt thereof, a solvate thereof, or an N-oxide thereof, or a prodrug thereof has an inhibitory activity against cysteine protease, and it is useful for the prophylaxis and/or treatment of a cysteine protease-related disease such as osteoporosis, etc.
Synthesis of pterocarpans through palladium-catalyzed oxyarylation of alkoxy-2H-chromenes with o-iodophenols
作者:Francisco V. Gaspar、Julio C.F. Barcellos、José F. Cívicos、Pedro Merino、Carmen Nájera、Paulo R.R. Costa
DOI:10.1016/j.tet.2020.131638
日期:2020.11
electron-donating (OMe) groups is studied under two experimental conditions: a) Pd(OAc)2, Ag2CO3 in PEG-400 at 140 °C, 10 min and b) oxime-based palladacycle, DIPEA, in PEG-400 at 150 °C, 3–4 h. Pterocarpans are obtained in moderate to good chemical yields.
A Highly Efficient and Broadly Applicable Cationic Gold Catalyst
作者:Deepika Malhotra、Mark S. Mashuta、Gerald B. Hammond、Bo Xu
DOI:10.1002/anie.201310239
日期:2014.4.22
Goldcatalysts capable of promoting reactions at low‐level loadings under mild conditions are the exception rather than the norm. We examined reactions where the regeneration of cationicgoldcatalyst (e.g., protodeauration) was the turnover limiting stage. By manipulating electron density on the substituents around phosphorus and introducing steric handles we designed a phosphine ligand that contains
Intramolecular Hydroarylation of Alkynes Catalyzed by Platinum or Gold: Mechanism andendo Selectivity
作者:Cristina Nevado、Antonio M. Echavarren
DOI:10.1002/chem.200401069
日期:2005.1
The cyclization of differently substituted aryl alkynes with PtII or AuI catalysts proceeds by endo-dig pathways. When AgI was used to generate reactive cationic AuI catalysts, 2H-chromenes dimerize to form cyclobutane derivatives by a AgI-catalyzed process. A DFT study on the cyclization mechanism shows a kinetic and thermodynamic preference for 6-endo-dig versus 5-exo-dig cyclizations in PtII-catalyzed