Bicyclic molecule

About: Bicyclic molecule is a research topic. Over the lifetime, 29587 publications have been published within this topic receiving 451252 citations. The topic is also known as: bicyclic molecule.

Effective Guanidine-Catalyzed Synthesis of Carbonate and Carbamate Derivatives from Propargyl Alcohols in Supercritical Carbon Dioxide

Abstract: The reactions of propargyl alcohols with carbon dioxide in supercritical carbon dioxide or in acetonitrile with gaseous carbon dioxide in the presence of organic bases as catalysts have been examined. Bicyclic guanidines are effective catalysts for the formation of α-methylene cyclic carbonates under mild reaction conditions. Oxoalkyl carbonates, oxoalkyl carbamates or α-methyleneoxazolidinones are obtained in high yields and good selectivities in one-step starting from propargyl alcohols and an external nucleophile (alcohols or amines) using bicyclic guanidines as catalysts in supercritical carbon dioxide. Propargylic diols under the same reaction conditions underwent a rearrangement process instead of carbon dioxide insertion whereas in the presence of an external nucleophile the formation of oxocarbonates, oxocarbamates or cyclic carbamates was achieved in satisfactory yields.

Substituted 6,5-hetero-bicyclic derivatives

Abstract: This invention relates to compounds of formula (I), wherein the dashed lines represent optional double bonds; A is nitrogen or CR7; B is -NR?1R2, -CR1R2R10-C(=CR2R11)R1, -NHCR1R2R10, -OCR1R2R10, -SCR1R2R10, -CR2R10NHR1, -CR2R10OR1, -CR2R10SR1? or -COR2; J and K are each independently nitrogen or carbon and both J and K are not nitrogens; D and E are each selected, independently, from nitrogen, CR4, C=O, C=S, sulfur, oxygen, CR?4R6 and NR8?; G is nitrogen or carbon; and their use for the prevention or inhibition of a disorder that can be treated by antagonizing CRF.

A selective and efficient method for alcohol oxidations mediated by N-oxoammonium salts in combination with sodium bromite

Abstract: Oxydation d'alcools primaires et secondaires en aldehydes, acides carboxyliques, et cetones

Single-component organic conductors based on neutral radicals containing the pyrazino-TCNQ skeleton

Abstract: Pyrazino-TCNQ (1a) prepared from 5, 8-diiodoquinoxaline (4a) is, like TCNQ itself, a strong electron acceptor and gives a stable anion radical salt as well as highly conductive charge-transfer crystals with donors. Substituted derivatives 1b-i were similarly prepared from 3,6-diiodo- 1,2-phenylenediamine (5) as a common intermediate, and bulky substituents such as the phenyl or pyridyl groups have very little effect on either the redox properties or planar geometry of 1a. Neutral radicals 3d-g derived from pyridyl-substituted derivatives 1d-g, respectively, are open-shell donor-[pi]-acceptor systems with high electrical amphotericity designed as a new motif for single-component organic conductors. The powder conductivity of 3f was as high as 3.2 [times] 10[sup [minus]5] S cm[sup [minus]1]. 29 refs., 4 figs., 2 tabs.

Eight-Membered Ring Construction by [4 + 2 + 2] Annulation Involving β-Carbon Elimination

Abstract: Cyclobutanones underwent a formal [4 + 2 + 2] annulation reaction with 1,6- and 1,7-diynes in the presence of nickel(0) catalysts to provide bicyclic eight-membered ring ketones. The annulation reaction proceeds through a ring-expansion of oxanickelacycloheptadiene via β-carbon elimination to form a nine-membered nickelacycle. This reaction employing cyclobutanones as a C4 unit constructs cyclooctadienone cores in one synthetic step.