26210-61-7

Upstream product

• 18080-94-9 1,1-diphenylsilene 
• 109-89-7 diethylamine 
• 144-79-6 chloromethyldiphenylsilane 

Relevant academic research and scientific papers

Kinetics and mechanism of the addition of aliphatic amines to transient silenes

Primary and secondary amines such as n-butyl-, t-butyl-, and N,N-diethylamine add across the Si=C bond of transient silenes such as 1,1-diphenylsilene (1a) and 1,1-bis(4-trifluoromethylpenyl)silene (1b) to yield the corresponding amino(methyl)diarysilanes as the only products of reaction. The kinetics and mechanism of reaction of these three amines with the two 1,1-diarylsilene derivatives have been studied in hexane, acetonitrile, and tetrahydrofuran (THF) solution by laser flash photolysis techniques, using the corresponding 1,1-diarylsilacyclobutanes as photochemical precursors to the silenes. The reactions proceed with clean second-order kinetics and bimolecular rare constants in excess of 5 × 108 M-1 s-1 in hexane and MeCN, with 1b being up to four times more reactive than 1a. Arhenius plots for reaction in hexane and/or acetonitrile solution show strong curvature over the 0-60°C temperature range, consistent with an addition mechanism involving the intermediacy of a zwitterionic silene-amine addition complex, which collapses to product by intramolecular proton transfer from nitrogen of the silenic carbon. The reactions are substantially slower in THF, where rate reductions on the order of 5-10-fold and 50-70-fold are observed for 1a and 1b, respectively, as compared to MeCN solution. This is due to the effects of complexation of the silenes with the ether solvent, the equilibrium constant for which enters the expression for the reaction rate constant in the complexing solvent. In contrast to the situation in hexane and MeCN. Arrhenius plots for reaction of n-BuNH2 wth 1a,b in THF solution are linear and lead to positive activation energies. Addition of amines in THF solution is proposed to occur predominantly via the free silenes but with minor contributions from a pathway involving nucleophilic displacement of the solvent from the silene-solvent complex.

19-Hydroxy-PGI2 compounds

Prostacyclin and prostacyclin-type derivatives having a 19-hydroxy feature are disclosed, including processes for preparing them and the appropriate intermediates. The compounds are useful for pharmacological purposes such as inhibition of blood platelate aggregation.

2-Decarboxy-2-hydroxymethyl-19-hydroxy-PG1 analogs

Prostaglandin derivatives having a 19,20-didehydro, a 19-hydroxy, or a 19-keto feature are disclosed, including processes for preparing them and the appropriate intermediates. A typical 19-hydroxy compound of this invention is 19-hydroxy-19-methyl-PGF2α, methyl ester, represented by the formula STR1

Bicyclic lactones

Process for preparing bicyclic lactone acrylic aldehydes and ketones of the formula STR1 wherein "n" is one or 2, wherein R1, is hydrogen, methyl, or ethyl, and wherein R4 is hydrogen or a blocking group; and those aldehydes, ketones, and intermediates prepared therein. The aldehydes and ketones are useful intermediates in preparing prostaglandins and analogs having pharmacological utility.