CNDO/2-calculations on energy surfaces, which describe the motion of the proton in intramolecular hydrogen bonds, were performed for two examples —β-hydroxypropionaldehyde and the enol of malondialdehyde. Intramolecular hydrogen bonds in systems without conjugation of acceptor and donator group and ...
structures • Molecules that use bonding and intermolecular forces will have weaker structures, where the strength depends upon the type of intermolecular force used • Molecules that use intermolecular forces and no bonding will have the weakest structures known; examples of these would be Noble ...
hydrogen bonding interaction thus favoring the nucleophilic addition of the neutral alkene (for examples of CPA activating carbonyl reactions see ref.38)38,39,40,41, while the enantioselectivity could be generated thanks to the presence of an additional hydrogen bond (HB) donor (HX) present in ...
79JHC409〉. The mechanism postulated for this reaction is dipolar addition to the 3,4-double bond of the dihydropyridine followed by hydrogen shift and loss of nitrogen. If the 1,2-dihydropyridine was not substituted on nitrogen then cyanogen azide reacted with the enamine double bond to give...
Examples of such rare events are shown in Fig. S6. This suggests that diffusion along the 1D reaction coordinate may not be strictly Markovian but instead depends on the conformation of the rest of the chain at any instant. Although the models used in this work, following traditional ...
cyclization and elimina- tion of hydrogen iodide; (ii) double electrophilic alkylation pathway (first, Friedel–Crafts alkylation between olefin and iodide; second, alkylation of enamine by the resulting carboca- tion, Fig. 2); (iii) radical mechanism by homo-cleavage of the C–I bond. We...
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Highly Regioselective Pd-Catalyzed Intermolecular Aminoacetoxylation of Alkenes and Evidence for cis-Aminopalladation and SN2 C−O Bond Formation Synthetic methods that achieve oxidative 1,2-difunctionalization of alkenes are very powerful in organic chemistry. Here we report the first examples of interm...
The regiochemistry observed is in agreement with CN bond formation by electrophilic nitrogen ahead of abstraction of allylic hydrogen by nitroso oxygen. Thus, reaction of 1- methylcyclohexene (70) with in situ generated nitrosocarbonylmethane yields a single product (71; equation 27).80 The chiral...
In the second type, hydrogen bond (HD) donor group (such as amide or phenol groups) at secondary coordination sphere acts as an intramolecular supporting site to stabilize M-CO2 adduct via an intramolecular hydrogen bond. In the third type, cis-coordination atoms in several cis-cobalt-complexes...