108 research outputs found
TransitionâMetalâFree CrossâCoupling of Benzothiophenes and Styrenes in a Stereoselective Synthesis of Substituted (E,Z)â1,3âDienes
A transition metalâfree oneâpot stereoselective approach to substituted (E,Z)â1,3âdienes was developed by using an interrupted Pummerer reaction/ligandâcoupling strategy. Readily available benzothiophene Sâoxides, which can be conveniently prepared by oxidation of the parent benzothiophenes, undergo Pummerer coupling with styrenes. Reaction of the resultant sulfonium salts with alkyllithium/magnesium reagents generates underexploited hypervalent sulfurane intermediates that undergo selective ligand coupling, resulting in dismantling of the benzothiophene motif and the formation of decorated (E,Z)â1,3âdienes
Age, Growth and Mortality of Atlantic chub mackerel, Scomber colias Gmelin, 1789 in the Mediterranean Waters of Morocco
This work is a study of growth aspects and mortality of the Atlantic chub mackerel, Scomber colia, from the Mediterranean Moroccan coast. A total of 845 specimens were collected from commercial catches in M'diq Bay, whose total length ranged between 16.4 and 35.9 cm. The length-weight relationship was W = 0.0019 TL3.4527 (r = 0.97) for the whole population. The Atlantic chub mackerel displays positive allometric growth. Otolith edge analysis indicated that opaque zones were formed between April and September and translucent ones during the remaining months of the year. The oldest individuals in the sample were 5 years old for both sexes. Von Bertalanffy growth parameters estimated for this species were: LâËĹž = 37.30 cm, k = 0.26 year-1 and t0 = - 2.19 year. The difference in growth between sexes is not significant. The estimated natural mortality was 0.59 per year
Sonogashira Reaction of Aryl Halides with Propiolaldehyde Diethyl Acetal Catalyzed by a Tetraphosphine/Palladium Complex.
Heck Arylations of Pent-4-enoates or Allylmalonate Using a Palladium/Tetraphosphine Catalyst.
Suzuki Coupling of Cyclopropylboronic Acid with Aryl Halides Catalyzed by a PalladiumâTetraphosphine Complex.
Synthesis of (E)-1-Aryl Alk-1-en-3-ones by Tetraphosphine/Palladium-Catalyzed Heck Reactions of Alk-1-en-3-one with Aryl Bromides.
ChemInform Abstract: Palladium-Tetraphosphine Complex Catalyzed Heck Reaction of Vinyl Bromides with Alkenes: A Powerful Access to Conjugated Dienes.
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