An increment system for deuterium isotope effects on13C chemical shifts of methylated benzenes
作者:Stefan Berger、Bernd W. K. Diehl
DOI:10.1002/mrc.1260241210
日期:1986.12
The complete series of all possible benzenes bearing one deuterium atom and one to five methyl groups was synthesized. The deuteriumisotopeeffects on the carbon chemicalshifts of the aromatic and aliphatic carbon atoms were measured and shown to obey an empirical increment system. The isotopeeffects over one bond correlate with the C,H spin coupling constants.
Intramolecular deuterium isotope effects in the meta photocycloaddition of aromatic compounds to alkenes
作者:P. de Vaal、G. Lodder、J. Cornelisse
DOI:10.1016/s0040-4020(01)87302-6
日期:1986.1
The effect of substitution of hydrogen by deuterium in some aromatic compounds on product distributions in the meta photocyloaddition to alkenes was investigated. The isotopeeffects found are in agreement with a polar mechanism.
Catalytic, Asymmetric Dearomative Synthesis of Complex Cyclohexanes via a Highly Regio- and Stereoselective Arene Cyclopropanation Using α-Cyanodiazoacetates
作者:Kendrick L. Smith、Cody L. Padgett、William D. Mackay、Jeffrey S. Johnson
DOI:10.1021/jacs.9b13080
日期:2020.4.8
has cumbered the development of novel intermolecular reactions that directly engage the arene pool. This paper describes a highly regio- and stereoselective, Rh2[(S)-PTTL]4-catalyzed arene cyclopropanation using α-cyanodiazoacetates to afford stable norcaradienes bearing three stereogeniccenters, one of which is an all-carbonquaternarycenter. The enantioenriched norcaradienes served as tunable templates
observed, which is different than the normal H/D kinetic isotope effects (KIEs) usually observed for polar aromatics. This result indicated that the oxidation started by photo-induced hvb+ can be the rate-determiningstep.
在TiO 2水溶液中弱极性芳族化合物的光催化羟基化反应中,观察到一系列的反向H / D KIE为0.7-0.8,这与通常在极性芳族化合物中观察到的正常H / D动力学同位素效应(KIEs)不同。该结果表明,由光诱导的h vb +开始的氧化可以是速率确定步骤。
Metal-Free sp<sup>2</sup>-C–H Borylation as a Common Reactivity Pattern of Frustrated 2-Aminophenylboranes
olefinic C-H bonds with 2-aminophenylboranes. Computational and experimentalstudies reveal that the metal-free C-H insertion proceeds via a frustrated Lewis pair mechanism involving heterolytic splitting of the C-H bond by cooperative action of the amine and boryl groups. The adapted geometry of the reactive B and N centers results in an unprecedentently low kinetic barrier for both insertion into the