Partial-state formalism and the object-subject split in quantum mechanics

A suitable general statistical framework is established by taking quantum mechanics as full, and other (state-distinguishing) statistical theories as partial theories with respect to a given relevant subset of observables. The partial theory exists and is unique up to equivalence. The choice of the simplest or canonical one is determined. The recently introduced hybrid, i.e., half quantum mechanical and half classical discrete, statistical states obtain thus their rightful place in a hierarchy of relevant quantum statistical theories. On the other hand, these states are shown to represent a derivation of the quantum object-subject split with a well-defined subject that encompasses preparator or measuring instrument in a natural way.     

Observation of coherent oscillation of a single nuclear spin and realization of a two-qubit conditional quantum gate

Rabi nutations of a single nuclear spin in a solid have been observed. The experiments were carried out on a single electron and a single 13C nuclear spin of a single nitrogen-vacancy defect center in diamond. The system was used for implementation of quantum logical NOT and a conditional two-qubit gate (CROT). Density matrix tomography of the CROT gate shows that the gate fidelity achieved in our experiments is up to 0.9, good enough to be used in quantum algorithms.     

Intramolecular alkene Friedel-Crafts cyclization of 1-allyl-1-N-(ortho-alkylphenylamino)cyclohexanes. A useful route to alkyl substituted dihydrospiro[(1H)quinoline-2,1-cyclohexanes]. Unprecedented ipso-substitution of alkyl groups

An unprecedented intramolecular Friedel-Crafts ipso-alkylation at the ortho-alkyl group of the N-arylamino moiety of 1-allyl-1-N-arylaminocycloalkanes to give alkyl substituted dihydrospiro[(1H) quinoline-2,1^′-cycloalkanes] is reported. Unexpected results were explained in the context of intramolecular ipso-substitution of alkyl groups and their 1,2-rearrangement. A plausible mechanism for this type of Friedel-Crafts alkylation by an alkene moiety promoted by a Brönsted acid (H₂SO₄) is proposed.     

A facile synthesis of 4-acylamino-tetrahydroindazoles via the Ritter reaction

A new route toward 4-acylamino- and 4-amino-substituted tetrahydroindazoles is disclosed. The title compounds are obtained in good to excellent yields in the Ritter reaction between 4-hydroxy-tetrahydroindazoles and various nitriles. The reactivity of the tetrahydroindazole-derived carbenium ion is both sufficiently high to react with trichloroacetonitrile and sufficiently selective to resist the azide functionality within its structure. The present approach adds a method to the toolbox of tetrahydroindazole chemistry and facilitates the structural modifications of the scaffold, which has found important applications in medicinal chemistry.     

Wagner-Meerwein skeletal rearrangement of 3-spiroannulated 6,8a-epoxy- and 6,8a;7,8-diepoxyisoquinolines (3-aza-11-oxatricyclo[6.2.1.0(1,6)]undec-9-enes). Isolation and identification of 5-aza-2-oxatricyclo[6.2.1.0(3,9)]undec-3-enes

The reactions of 3-acetyl-3-aza-11-oxatricyclo[6.2.1.0(1,6)]undec-9-ene and its 9,10-epoxy derivative with bromine and Ac(2)O/BF(3).OEt(2) under different conditions were studied. Unusual products of Wagner-Meerwein rearrangement bearing the olefin fragment (5-aza-2-oxatricyclo[6.2.1.0(3,9)]undecen-3-enes) were isolated and characterized by X-ray analysis.