The xanthate route to tetralones, tetralins, and naphthalenes. A brief account

The present account summarises routes to tetralones, tetralines, and naphthalenes based on the chemistry of xanthates developed in the authors' laboratory. The degenerative reversible transfer of xanthates allows radical addition even to unactivated, electronically unbiased alkenes, and tolerates a broad range of functional groups, in particular common polar groups such as esters, ketones, nitriles, amides, carbamates, etc. Xanthates also allow radical ring closures onto aromatic rings. This feature, in combination with the intermolecular addition to alkenes, can be used to construct tetralones and tetralines. With the appropriate appendages, the former can be converted into napthalenes with a variety of substitution patterns. This translates into a convergent approach to a vast array of building blocks of interest to the pharmaceutical and agrochemical industries, and to material sciences.

Aminolactonization of Unactivated Alkenes Catalyzed by Aryl Iodine

A one-step protocol of the aryl iodine-catalyzed aminolactonization of unactivated alkenes under oxidation conditions was first reported to efficiently construct diverse amino lactones in a short time using HNTs₂ as the compatible nitrogen source. In addition, we investigated the influence of the reaction rate based on the structure of the iodoarene precatalyst, which revealed the selective adjustment effect on aminolactonization and oxylactonization. Finally, preliminary experiments verified the feasibility of asymmetric aminolactonization catalyzed by a chiral iodoarene precatalyst.

The role of 5ht2c receptors in affective disorders

5-HT(2C) receptors are predominantly localised in the brain and their dysregulation may contribute to particular symptoms of anxiety and depression. The marked affinity of several clinically established psychotropic agents sites (e.g., tricyclic antidepressants, clozapine, fluoxetine) for 5-HT(2C) receptor has generated interest in the therapeutic potential of selective, high affinity 5-HT(2C) receptor ligands. Like the selective serotonin re-uptake inhibitor (SSRI) fluoxetine, high affinity selective agonists such as Ro 60-0175 and Ro 60-0332 have potent in vivo activity in animal models suggestive of therapeutic action against depression, obsessive-compulsive disorder (OCD) and panic disorders. In contrast, 5-HT(2C) receptor antagonists such as SB-200646A or SB-221284 show signs of anxiolytic-like activity in tests for conditioned and phobic-like anxiety in rodents whereas they are inactive in tests indicative of antidepressant, antiOCD and antipanic activity. These results are consistent with an important hypothesis proposing that 5-HT has a complex, dual action on the neural mechanism of anxiety by either facilitating or inhibiting different kinds of anxiety in different brain regions. They also suggest that 5-HT(2C) receptor subtypes play an important role in the therapeutic properties of SSRIs. Certain 5-HT(2C) receptor antagonists may possess negative efficacy at 5-HT(2C) receptors and, as inverse agonists, may control constitutive receptor activity possibly characterising some psychopathological states. Receptor variants exist in the human population and indicate possible associations between somatic mutations in the 5-HT(2C) receptor and psychopathology or response to drug treatment. Selective 5-HT(2C) receptor ligands may offer innovative and improved therapeutic opportunities for the biological treatment of specific aspects of psychiatric syndromes.

Total Synthesis of 10-Norparvulenone and of O-Methylasparvenone Using a Xanthate-Mediated Free Radical Addition−Cyclization Sequence

[reaction: see text] A short synthesis of (+/-)-10-norparvulenone and (+/-)-O-methylasparvenone was developed starting from commercially available m-methoxyphenol, hinging on a xanthate-mediated addition-cyclization sequence for the construction of the alpha-tetralone subunit.