55668-09-2

Upstream product

• 818-23-5 8-Pentadecanon 
• 1779-49-3 Methyltriphenylphosphonium bromide 
• 13125-66-1 n-heptylmagnesium bromide 
• 1653-35-6 pentadecan-8-ol 
• 124-13-0 Octanal 

Relevant academic research and scientific papers

Contra-thermodynamic Olefin Isomerization by Chain-Walking Hydroboration and Dehydroboration

We report a dehydroboration process that can be coupled with chain-walking hydroboration to create a one-pot, contra-thermodynamic, short-or long-range isomerization of internal olefins to terminal olefins. This dehydroboration occurs by a sequence comprising activation with a nucleophile, iodination, and base-promoted elimination. The isomerization proceeds at room temperature without the need for a fluoride base, and the substrate scope of this isomerization is expanded over those of previous isomerizations we have reported with silanes.

Temperature-controlled divergent synthesis of 4-alkoxy- or 4-alkenyl-chromanes via inverse electron-demand cycloaddition with in situ generated ortho-quinone methides

The temperature-controlled divergent synthesis of 4-alkoxy- or 4-alkenyl-chromanes via inverse electron-demand cycloaddition with in situ generated ortho-quinone methides under identical reaction conditions except for thermal condition has been developed. At room temperature, the reaction generated 4-methoxychromanes, whereas the reaction performed at room temperature to 100 °C gave 4-alkenylchromanes. Trifluoromethanesulfonic acid was efficiently suitable in the reaction to give the 4-substituted chromanes. This divergent synthetic strategy exhibits a new method giving carbon–carbon or carbon–oxygen bond by controlling the reaction temperature.

Slippage of a porphyrin macrocycle over threads of varying bulkiness: Implications for the mechanism of threading polymers through a macrocyclic ring

Threading of a polymer through a macrocyclic ring may occur directly, that is, by finding the end of the polymer chain, or by a process in which the polymer chain first folds and then threads through the macrocyclic ring in a hairpin-like conformation. We present kinetic and thermodynamic studies on the threading of a macrocyclic porphyrin receptor (H21) onto molecular threads that are blocked on one side and are open on the other side. The open side is modified by groups that vary in ease of folding and in bulkiness. Additionally, the threads contain a viologen binding site for the macrocyclic receptor, which is located close to the blocking group. The rates of threading of H21 were measured under various conditions, by recording as a function of time the quenching of the fluorescence of the porphyrin, which occurs when receptor H21 reaches the viologen binding site. The kinetic data suggest that threading is impossible if the receptor encounters an open side that is sterically encumbered in a similar way as a folded polymer chain. This indicates that threading of polymers through macrocyclic compounds through a folded chain mechanism is unlikely.

METHYLENATION OF CARBONYL COMPOUNDS WITH METHYLENEDIMAGNESIUM IODIDE IN THE PRESENCE OF Et2AlCl

A method has been developed for the methylenation of carbonyl compounds with methylenedimagnesium iodide in the presence of Et2AlCl in 35-70percent yield.In the presence of catalytic amounts of Ti and Pd complexes the yield of methylenation products is increased by 15-20percent.

Synthetic and Mechanistic Aspects on the Wittig Reaction. A Yield Increasing Modification

In the Wittig reaction between ketones and methylenetriphenylphosphorane in ether, enolization of the ketone is shown to be an important side-reaction that in many cases decreases the yield substantially.To avoid this, repeated additions of stoichiometric amounts of water (to regenerate the ketone) and the phosphorane were made.In a typical example , the yield of olefin was raised from 38 to 89percent by this procedure.