Dual Activation Strategy to Achieve C-C Cleavage of Cyclobutanes: Development and Mechanism of Rh and Zn Cocatalyzed [4 + 2] Cycloaddition of Yne-Vinylcyclobutanones.

Reported here is the Rh and Zn cocatalyzed [4 + 2] cycloaddition of newly designed yne-vinylcyclobutanones, which can generate 5/6 or 6/6 bicyclic products with an all-carbon quaternary bridgehead center. The reaction has a broad scope and can realize chirality transfer from enantioenriched substrates to the cycloadducts. The key to the success of this [4 + 2] reaction is the introduction of a vinyl group to cyclobutanones, which helps the C-C cleavage of vinylcyclobutanones via oxidative addition.

DFT study on the mechanism of bimetallic Pd-Zn-catalyzed cycloaddition of alkynyl aryl ethers with internal alkynes.

The reaction mechanism of bimetallic Pd-Zn-catalyzed cycloaddition of alkynyl aryl ethers with internal alkynes has been studied theoretically. Besides cycloaddition reaction, the dimerization of alkynyl aryl ethers was also considered. Both C6H5OC[triple bond, length as m-dash]CSiiPr3 and C6H5OC[triple bond, length as m-dash]CSiMe3 were chosen as the substrates.

[Experiment on pruning of Cistanche deserticola inoculated in artificial Haloxylon ammodendron forest].

At present, the objective of cutting and pruning Cistanche deserticola is to harvest in successive years and enhance the harvesting yield and quality of C. deserticola in the process of the artificial cultivating C. deserticola.

Bis(2-hydroxy-imino-methyl-6-methoxy-phenolato-κO,N)nickel(II).

The Ni atom in the title compound, [Ni(C(8)H(8)NO(3))(2)], lies on a center of inversion in a square-planar coordination enviroment. The hydroxyl group of one anion forms a short hydrogen bond to the metal-coordinated O atom of the other anion.