Parallel mechanisms for the cycloaromatization of enyne allenes †
作者:Thomas S. Hughes、Barry K. Carpenter
DOI:10.1039/a904369a
日期:——
The Myers–Saito cycloaromatization of enyne allenes is proposed to consist of two parallel mechanisms, one involving a biradical and the other with dipolar character. MCSCF calculations suggest that a nonplanar cyclic allene could be fairly close in enthalpy to the biradical, while the planar zwitterion originally proposed as a possible second intermediate is in fact a transition state for the interconversion
1.0]hex-2-ene systems led to the conclusion that drastically different mechanisms operate for the two reactions. Activation parameters, solvent effects, kinetic isotope effects, isotope labelling experiments and observation of reactive intermediates all contributed to the conclusion that the reaction of 6,6-difluorobicyclo[3.1.0]hex-2-ene, 1, proceeds via a homolytic hydrogen-shift rearrangement, while
This invention relates to deuterated forms of hexahydro-4,7-methano-1H-isoindole-1,3(2H)-diones, and pharmaceutically acceptable salts thereof. In one aspect, the invention provides a compound of Formula (I): or a pharmaceutically acceptable salt thereof. This invention also provides compositions comprising a compound of this invention, including pharmaceutical compositions comprising the compound and a pharmaceutically acceptable carrier. This invention also provides the use of such compounds and compositions in methods of treating diseases and conditions that are beneficially treated by administering a compounds that modulates the activity of a receptor selected from the group consisting of central dopamine Type 2 (D2) receptor and serotonin Type 2 (5HT2A) receptor. Some exemplary embodiments include a method of treating a disease or condition selected from schizophrenia and depressive episodes associated with bipolar I disorder, the method comprising the step of administering to a subject in need thereof a pharmaceutically acceptable composition of the present invention.
Examining the Effects of Monomer and Catalyst Structure on the Mechanism of Ruthenium-Catalyzed Ring-Opening Metathesis Polymerization
作者:William J. Wolf、Tzu-Pin Lin、Robert H. Grubbs
DOI:10.1021/jacs.9b08835
日期:2019.11.6
monomer-dependent mechanism for polymerization of norbornene monomers using these fast-initiating catalysts. A series of kinetic experiments, including rate measurements for ROMP, rate measurements for initiation, monomer-dependent kinetic isotope effects, and activation parameters were useful for distinguishing chelating and nonchelating monomers and determining the effect of chelation on the polymerization
作者:Asli Cangönül、Maike Behlendorf、Andreas Gansäuer、Maurice van Gastel
DOI:10.1021/ic401403a
日期:2013.10.21
species has not been directly observed. However, by a combination of isotopelabeling and spin-trapping, evidence for the existence of such a species has been unequivocally demonstrated. The observation of a titanocene(III)–epoxide complex is unprecedented and provides directevidence for inner-sphere electron transfer between epoxides and titanocenes, responsible for the high regioselectivity of ring-opening