Enantioselective Conjugate Addition of Alkenyl Trifluoroborates to Alkenyl-Substituted Benzimidazoles Catalyzed by Chiral Binaphthols.

The enantioselective organocatalytic conjugate alkenylation of β-substituted alkenyl benzimidazoles afforded β-stereogenic 2-alkyl benzimidazole derivatives in excellent enantioselectivities. Chiral binaphthols were effective catalysts for promoting the nucleophilic addition of bench-stable alkenyl trifluoroborate salts under mild conditions, expanding their applications by utilizing C=N-containing azaarenes as activating groups. The synthetic utility of this strategy is demonstrated by conversions into several useful enantiomerically enriched benzimidazole building blocks.

Kinetic Resolution of Tertiary Allylic Alcohols: Highly Enantioselective Access to Cyclic Ethers Bearing an α-Tetrasubstituted Stereocenter.

A chiral phosphoric acid-catalyzed kinetic resolution of tertiary allylic alcohols was developed to provide structurally valuable enantioenriched 2,2-disubstituted tetrahydrofurans, tetrahydropyrans, and oxepane. A variety of tertiary allylic alcohols were resolved with selectivity factors of ≤120. A tertiary allylic carbocationic intermediate mediates the enantioselective intramolecular substitution to achieve high regio- and enantioselectivity.

Organocatalytic Enantioselective Conjugate Alkynylation of β-Aminoenones: Access to Chiral β-Alkynyl-β-Amino Carbonyl Derivatives.

Readily available potassium alkynyltrifluoroborates were used for organocatalytic asymmetric conjugate alkynylation of β-enaminones. The interception of a modified binaphthol catalyst and in situ generated organodifluoroboranes proved important to access functionalized β-alkynyl-β-amino carbonyls and derivatives with improved chemo-reactivity and enantio-induction. Mechanistic studies revealed the impact of molecular sieves on efficiency and stereocontrol.

Superhydrophobic foam prepared from high internal phase emulsion templates stabilised by oyster shell powder for oil-water separation.

In this paper, poly(styrene-divinylbenzene) foams were synthesized using a high internal phase emulsion (HIPE) technique with Span 80 and with 900 °C calcined oyster shell powder as a co-emulsifier, 2,2'-azobisisobutyronitrile (AIBN) as an initiator and deionized water as the dispersing phase. SEM images revealed that the materials possess a hierarchical porous structure of nano/micro size, which resulted in saturated oil adsorption in only half a minute. The dispersing phase amount was investigated for its effect on adsorption.

Synthesis and bioactivity evaluation of novel spiromesifen derivatives.

Background: The development of environmentally friendly and novel structural pesticides is now an area of intense research in the agriculture field. Spirocyclic tetronic acids such as spiromesifen are typical compounds of this kind. In order to discover novel compounds with improved and broader-spectrum insecticidal activities, a series of spiromesifen derivatives were synthesised and bioassayed.

3-Mesityl-2-oxo-1-oxaspiro-[4.4]non-3-en-4-yl benzoate.

In the title compound, C(24)H(24)O(4), a derivative of the potent insecticide and miticide spiro-mesifen, one cyclo-pentane C atom is disordered over two positions with occupancies of 0.574 (12) and 0.426 (12), resulting in respective envelope and twisted conformations for the cyclo-pentane ring.

3-(2,4-Dichloro-phen-yl)-2-oxo-1-oxaspiro-[4.5]dec-3-en-4-yl acetate.

In the title compound, C(17)H(16)Cl(2)O(4), the cyclo-hexyl ring displays a chair conformation [the four C atoms are planar with a mean deviation of 0.001 (2) Å and the two C atoms at the flap positions deviate by 0.625 (2) and -0.

3-Mesityl-2-oxo-1-oxaspiro-[4.4]non-3-en-4-yl 2-(4-chloro-phen-yl)-3-methyl-butyrate.

In the title compound, C(28)H(31)ClO(4), the five-membered cyclo-pentyl ring displays an envelope conformation with the atom at the flap position 0.519 (3) Å out of the mean plane formed by the other four atoms. The furan ring makes dihedral angles of 72.