Rapid Assembly of Substituted Dihydrocyclohepta[3,4]pyrrolo[1,2-a]indoles via a Novel, Carbene-Based, Rearrangement Reaction

Computational Assessment of the Electronic Structure of 1‐Azacyclohexa‐2,3,5‐triene (3δ2‐1H‐Pyridine) and Its Benzo Derivative (3δ2‐1H‐Quinoline) as well as Generation and Interception of 1‐Methyl‐3δ2‐1H‐quinoline

“…Obviously, in the case of the ground state of 6, which has a closed-shell single-determinant nature, the DFT methods perform better than CASSCF calculations, since they offer a more balanced description of dynamic and nondynamic correlation effects. The results of the CASSCF and DFT calculations are in much better agreement for the species 6 b and 6 c, where the larger [8,7] active space could be used. In general, the geometries optimised with DFT methods gave lower absolute single-point energies at the CASPT2 level, and we will focus on these structures in the following.…”

“…All DFT calculations were performed with the Gaussian 98 program package. [24] A comparison of different choices for the active space in the CAS treatment showed that an adequate description in C s symmetry (compounds 6 b and 6 c) includes the three occupied a'' (p) orbitals with the corresponding number of virtual orbitals and the nonbonding a' (s) orbital mainly located at the central allene carbon, thus defining an [8,7]-CASSCF method. The active space for the C 1 -symmetrical species 6 a was chosen as the three highest occupied and three lowest unoccupied molecular orbitals (MOs) of the a irreducible representation, leading to a calculations were performed with the MOLCAS program package.…”

“…consider more closely the allene form 6 a and the singlet diradical 1 6 c. The possible intervention of derivatives of 3d 2 -1H-quinoline (8) in the thermolysis of 1-(2-amino-5-chlorophenyl)propargyl carboxylates has recently been advanced by Frey et al [8] Herein, we report the generation of 1-methyl-3d…”

Deciphering the Mechanistic Dichotomy in the Cyclization of 1-(2-Ethynylphenyl)-3,3-dialkyltriazenes: Competition between Pericyclic and Pseudocoarctate Pathways

“…To lend further evidence to the carbene intermediate, we attempted cyclization to the isoindazole with a starting compound that could trap the carbene intramolecularly. Saito and co-workers have shown that the use of a biphenyl moiety allows carbenes to be trapped as fluorenes. Ethynylphenyltriazene 1c (R = Me) was coupled to 2-iodobiphenyl under Sonogashira conditions to give 8 in 75% yield (Scheme ).…”

Synthesis and Some Biological Properties of Pyrrolo[1,2‐a]indoles

“…The authors of performed a detailed study of optically active alcohol 249 transformations with production of pyrroloindoles 250 and 251 depending on the steric crowding of the nitrogen atom. Upon reaction with carbonyl dimiidazole, СО bond in 249 breaks with the closure of the indole cycle and production of intermediate carbene 252 .…”