A Convenient Synthesis of 3-Aryl-2-Methyl-3,4-Dihydro-1(2H)-Isoquinolones and -1,2,3,4-Tetrahydroisoquinolines

A new methodology for the synthesis of 3-aryl-2-methyl-3,4-dihydro-2H-isoquinolin-l-ones and 3-aryl-2-methyl-1,2,3,4-tetrahydroisoquinolines is reported.     

Suzuki-Miyaura cross-coupling and ring-closing metathesis: a strategic combination to the synthesis of indeno[1,2-c]isoquinolin-5,11-diones

A variety of diversely substituted isoindeno[1,2-c]isoquinolin-5,11-diones has been readily assembled through a sequence involving a Suzuki-Miyaura cross-coupling reaction with enol phosphates combined with a ring-closing metathesis (RCM) reaction. Intramolecular carbocationic annulation reaction and ultimate oxidation of a latent hydroxyl functionality completed the synthesis of the target titled compounds.     

Triggering and guiding of an upward positive leader from a ground rod with an ultrashort laser pulse. II. Modeling

We have used the Bondio-Gallimberti model of positive leader propagation to simulate laboratory experiments of laser triggering and guiding of upward leaders initiated from a ground rod. The model proves to be capable of reproducing all the important features of laser-guided leader propagation that have been observed experimentally. The leader guiding effect of the laser-created plasma channel is taken into account in the model by adjusting the value of the charge per unit length of the leader, which has been measured in the laboratory to be lower for a laser-guided leader than for an ordinary one. The charge per unit length of the leader is related in the model to the critical temperature at which the air in the transition region at the leader tip must be heated to be conductive enough to become a new leader portion. For an ordinary leader, this critical temperature is 1500 K, at which the electrons all detach from the negative ions in the leader corona, increasing the air conductivity. We give the interpretation that in the case of the laser-guided leaders, because of the relatively high density of negative ions per unit length in the laser-ionized channel, the right conditions of conductivity can be met in the transition region without the electrons being all detached from the ions, allowing a reduction of the critical temperature and of the charge per unit length.     

A concise first total synthesis of narceine imide

A concise and efficient total synthesis of alkaloid narceine imide is disclosed. The key steps are based upon the sequential construction of the isoindolinone template followed by metalation and coupling with an isoquinolinium salt. Subsequent E1cb elimination enables the creation of the arylmethylene unit with the concomitant formation of the dimethylaminoethyl chain and ultimate deprotection completes the synthesis of the natural product.     

Asymmetric synthesis of 3- or 4-alkyl or arylbenzo[c]azepines

Two flexible routes for the stereoselective synthesis of a variety of 3- or 4-alkylated or arylated tetrahydrobenzazepines have been developed. The key steps are the highly diastereoselective metallation/alkylation reaction and 1,2-addition processes applied to stereopure SAMP hydrazones combined with a cyclomethylenation reaction.     

Chrom, Vanadin

Ohne Zusammenfassung     

Photoreduction de la benzophenone par des thioethers etudiee par pnic

CIDNP (Chemically Induced Dynamic Nuclear Polarization) studies of the photoreduction of benzophenone by R-CH₂-S-R' show evidence for the $\text{formation of vinylic}$ deratives and adducts. The central intermediate in the reaction scheme is the radical pair R-CH-S-R' φ₂-C-OH^t. A study with selenides shows a different behaviour for these compounds.