Dioxygen-Promoted Regioselective Oxidative Heck Arylations of Electron-Rich Olefins with Arylboronic Acids
作者:Murugaiah M. S. Andappan、Peter Nilsson、Henrik von Schenck、Mats Larhed
DOI:10.1021/jo049434t
日期:2004.8.1
with arylboronicacids. This appears to constitute the first example of palladium(II)-catalyzed internal Heck arylations. The novel protocol exploits oxygen gas for environmentally benign reoxidation and a stable 1,10-phenanthroline bidentate ligand to promote the palladium(II) regeneration and to control the regioselectivity. Internal arylation is strongly favored with electron-rich arylboronic acids
Bipyridine-Modulated Palladium-Catalyzed Oxidative Heck-Type Reactions of Arylboronic Acids with Olefins
作者:Chien-Ming Hsu、Chih-Bin Li、Chia-Hsing Sun
DOI:10.1002/jccs.200900129
日期:2009.10
We have demonstrated that 4,4′‐dimethyl 2,2′‐bipyridine as ligand for Pd(II) catalysts was very efficient for oxidativeHeck‐type coupling reaction of arylboronicacids with olefins in DMA or CH3CN under atm air at 80 °C. The presence of chelated bipyridine ligand isindispensable to achieve high reaction yields and to suppress the formation of biphenyl as homocoupled byproduct.
Selective Terminal Heck Arylation of Vinyl Ethers with Aryl Chlorides: A Combined Experimental−Computational Approach Including Synthesis of Betaxolol
作者:Gopal K. Datta、Henrik von Schenck、Anders Hallberg、Mats Larhed
DOI:10.1021/jo0602367
日期:2006.5.1
medium. The selectivity for linear β-product in PEG-200 is slightly higher than in aqueous DMF. DFT calculations support a ligand-driven selectivity rationale, where the electronic and steric influence of bulky P(t-Bu)3 ligand provides improved β-selectivity in the essential insertion step also with electron-rich aryl chlorides. A tentative computational rationalization of the improved selectivity in non-methylated
Rearrangement of isoxazoline-5-spiro derivatives. Part 7. Thermal rearrangement of 4,5-dihydro and tetrahydroisoxazole-5-spirocyclobutanes to azepin-4-one derivatives
作者:Andrea Goti、Alberto Brandi、Francesco De Sarlo、Antonio Guarna
DOI:10.1016/s0040-4020(01)89026-8
日期:——
respectively. When subjected to flash vacuum thermolysis conditions, the spiranic cycloadducts rearranged to afford mainly the desired azepin-4-one derivatives. In addition, the isoxazoline cycloadducts gave unexpected by-products, which were identified as 1-alkenyl-2-pyrrolidinones. Analogies and differences with respect to the lower homologue cyclopropanes are evidenced in both cycloaddition and rearrangement
The present invention relates to modulators of muscarinic receptors. The present invention also provides compositions comprising such modulators, and methods therewith for treating muscarinic receptor mediated diseases.