Development of Gold-catalyzed [4+1] and [2+2+1]/[4+2] Annulations between Propiolate Derivatives and Isoxazoles
作者:Rajkumar Lalji Sahani、Rai-Shung Liu
DOI:10.1002/anie.201610665
日期:2017.1.19
new gold‐catalyzed annulations of isoxazoles with propiolates have been developed. Most isoxazoles follow an initial O attack on the alkyne to afford a [4+1] annulation product. This process results in a remarkable alkyne cleavage of initial propiolates. Unsubstituted isoxazoles proceed through an N attack step to yield formal [2+2+1]/[4+2] annulation products. These two annulation products arise initially
1, 3-Dipolar cycloaddition reaction of trimethylstannylacetylene with nitrile oxides yielded 3-substituted 5-(trimethylstannyl)isoxazoles. On the other hand, the same reaction of (trimethylstannyl)phenylacetylene, -1-hexyne, and -(trimethylsilyl)acetylene gave 3, 5-disubstituted 4-(trimethylstannyl)isoxazoles almost regioselectively. The regioselectivity of the cycloaddition reaction is interpreted by application of the frontier-electron theory.
Compounds, compositions and methods are provided which are useful in the treatment of diseases through the inhibition of sodium ion flux through voltage-gated sodium channels. More particularly, the invention provides substituted sulfonamides, compositions comprising these compounds, as well as methods of using these compounds or compositions in the treatment of central or peripheral nervous system disorders, particularly pain and chronic pain by blocking sodium channels associated with the onset or recurrence of the indicated conditions. The compounds, compositions and methods of the present invention are of particular use for treating neuropathic or inflammatory pain by the inhibition of ion flux through a voltage-gated sodium channel.
SUBSTITUTED N-HETEROCYCLYL- AND N-HETEROARYL-TETRAHYDROPYRIMIDINONES AND THE SALTS THEREOF, AND THE USE OF SAME AS HERBICIDAL ACTIVE SUBSTANCES
申请人:Bayer Aktiengesellschaft
公开号:US20200390100A1
公开(公告)日:2020-12-17
The present invention relates to substituted N-heterocyclyl- and N-heteroaryltetrahydropyrimidinones of the general formula (I) or salts thereof,
where the radicals in the general formula (I) correspond to the definitions given in the description, and to the use thereof as herbicides, in particular for controlling broad-leaved weeds and/or weed grasses in crops of useful plants and/or as plant growth regulators for influencing the growth of crops of useful plants.
3,5-Dimethylisoxazole (1) was alkylated with sodium amide in liquid ammonia to give 3-methyl-5-alkylisoxazoles. By di- and tri-alkylation reactions using excess sodium amide, isoxazoles having secondary and tertiary alkyl groups at 5-position could be obtained. The hydrogenolysis and hydrolysis of these isoxazoles were also studied.