Hydroalkoxylation of Unactivated Olefins with Carbon Radicals and Carbocation Species as Key Intermediates
摘要:
A unique Markovnikov hydroalkoxylation of unactivated olefins with a cobalt complex, silane, and N-fluoropyridinium salt is reported. Further optimization of reaction conditions yielded high functional group tolerance and versatility of alcoholic solvent employed, including methanol, i-propanol, and t-butanol. Use of trifluorotoluene as a solvent made the use of alcohol in stoichiometric amount possible. Mechanistic insight into this novel catalytic system is also discussed. Experimental results suggest that catalysis involves both carbon radical and carbocation intermediates.
Copper-Catalyzed Direct C–H Alkylation of Polyfluoroarenes by Using Hydrocarbons as an Alkylating Source
作者:Weilong Xie、Joon Heo、Dongwook Kim、Sukbok Chang
DOI:10.1021/jacs.0c00169
日期:2020.4.22
Construction of carbon-carbon bonds is one of the most important tools in chemical synthesis. In the previously established cross-coupling reactions, prefunctionalized starting materials are employed usually in the form of aryl- or alkyl (pseudo)halides or their metallated derivatives. However, direct use of arenes and alkanes via a twofold oxidative C-H bond activation strategy to access chemoselective C(sp2)-C(sp3)
A new method for the preparation of tertiary butyl ethers and esters
作者:Alan Armstrong、Ian Brackenridge、Richard F.W. Jackson、Joanna M. Kirk
DOI:10.1016/s0040-4039(00)87913-7
日期:1988.1
T-butyl 2,2,2-trichloroacetimidate (1), readily prepared by addition of t-butanol to trichloroacetonitrile, is an efficient reagent for the preparation of t-butyl ethers and esters in the presence of a catalytic amount of boron trifluoride etherate.
Lipase‐Mediated Conversion of Protecting Group Silyl Ethers: An Unspecific Side Reaction
作者:Lisa M. Pick、Jessica Wenzlaff、Mohammad Yousefi、Mehdi D. Davari、Marion B. Ansorge‐Schumacher
DOI:10.1002/cbic.202300384
日期:2023.9.15
Silyl ethers are important protectinggroups in organic synthesis and a selective cleavage or formation is highly desirable. The ability of lipases to catalyze the reactions has long been suspected. This study gives experimental and structural evidence that both cleavage and formation of trimethyl ethers are promoted by lipases, but not at the active site.
This invention relates to compounds that are agonists of the muscarinic M1 and/or M4 receptor and which are useful in the treatment of diseases mediated by the muscarinic M1 and M4 receptors. Also provided are pharmaceutical compositions containing the compounds and the therapeutic uses of the compounds. Compounds provided are of formula (1)
wherein X1; X2; R1 and R4 are as defined herein.
BiBr3, an efficient catalyst for the benzylation of alcohols: 2-phenyl-2-propyl, a new benzyl-type protecting group
作者:Bernard Boyer、El-Mehdi Keramane、Jean-Pierre Roque、André A Pavia
DOI:10.1016/s0040-4039(00)00304-x
日期:2000.4
The benzylation of aliphatic alcohols with various benzylic alcohols has been achieved in the presence of BiBr3 under mild conditions. 2-Phenylpropan-2-ol proved to be the most efficient and can be considered as a novel protecting group. (C) 2000 Elsevier Science Ltd. All rights reserved.