Nitrile-substituted cyclopropanes are readily synthesized in a stereocontrolled fashion from the intermolecular cyclopropanation between 2-diazo-2-phenylacetonitrile and electron-rich olefins, catalyzed by the chiral dirhodium complex, Rh(2)(S-PTAD)(4).

Introduction Middle 1950s may be treated as the beginning of the age of plastics – their global production in last 60 years have increased from approx. 1.5 mln to almost 290 mln tons. The dominating position in production and consumption of these materials for many years has been occupied by polyolefins (in Europe 48% from 57 mln tons of plastics) [1]. Forecasters predict that in coming years t...

Aqueous catalytic polymerization may seem like a contradiction at first sight. The high water sensitivity of Ziegler or Phillips catalysts applied commercially for the production of polyolefins is well known. However, water offers a unique combination of properties as a medium for polymerization reactions: A high heat capacity, which enables an effective transfer of the heat of polymerization. ...

Light olefins are the main building blocks used in petrochemical and chemical industries for production of different components such as polymers, synthetic fibers, rubbers, plastic materials. Currently, steam cracking hydrocarbons is technology light olefins. In cracking, pyrolysis feedstocks occurs furnace, where hydrocarbon feed first mixed preheated convection section then enter furnace radi...

The largest industrial application of olefin metathesis today is the synthesis of propylene from ethylene and butenes employing WO3 on SiO2, a relatively long-lived and regenerable catalyst that operates at 350–400 °C. It is widely proposed that high temperatures are required because the percentage of metal sites actually involved in the metathesis reaction is extremely low, or the reaction tha...

From our investigations on phosphine-catalyzed [4+2] annulations between α-alkyl allenoates and activated olefins for the synthesis of cyclohexenes, we discovered a hexamethylphosphorous triamide (HMPT)-catalyzed [4+2] reaction between α-alkyl allenoates 1 and arylidene malonates or arylidene cyanoacetates 2 that provides highly functionalized cyclohexenes 3 and 4 in synthetically useful yields...

Stereodefined enol derivatives of aldehydes are prepared from terminal alkynes. Specifically, terminal alkynes are known to undergo Cp2ZrCl2-catalyzed methylalumination. Here, we show that the resultant vinylalanes can be oxygenated with peroxyzinc species to generate trisubstituted enolates. Electrophilic trapping with carboxylic anydrides or silyl triflates yields trisubstituted enol esters o...