513-31-5Relevant articles and documents
Cyclohexyne cycloinsertion in the divergent synthesis of guanacastepenes
Gampe, Christian M.,Carreira, Erick M.
, p. 15761 - 15771 (2012)
The guanacastepenes are a family of 15 diterpenes that share a common 5-6-7 tricyclic core, which is decorated with quaternary centers, unsaturation, hydroxyl and carbonyl groups. Some of these natural products show interesting antimicrobial potency. Their collective structural and biological features have stirred up vibrant activity among organic chemists. Herein, we disclose an account of our studies toward the synthesis of a number of guanacastepenes. The synthetic strategy relies on the use of cyclohexyne in a cycloinsertion reaction to rapidly construct the guanacastepene core. Isolation of a cyclobutenol as intermediate in the cyclohexyne cycloinsertion provided us with the possibility to study further the reactivity of this metastable compound, and we uncovered novel rearrangements and ring-opening reactions. Stereoselective, late-stage oxidative diversification of the carbon scaffold allowed the synthesis of guanacastepenes N and O and paved the way for the synthesis of guanacastepenes H and D. No strain, no gain! Studies toward the synthesis of the guanacastepene family of diterpenes are presented. The synthetic strategy relies on the use of cyclohexyne as the guanacastepene C-ring, which undergoes cycloinsertion to form the tricyclic carbon scaffold. A host of procedures developed for the diversification of the carbon core allowed the synthesis of guanacastepenes N and O and paved the way for the synthesis of guanacastepenes D and H. Copyright
Ynamide Carbopalladation: A Flexible Route to Mono-, Bi- and Tricyclic Azacycles
Campbell, Craig D.,Greenaway, Rebecca L.,Holton, Oliver T.,Walker, P. Ross,Chapman, Helen A.,Russell, C. Adam,Carr, Greg,Thomson, Amber L.,Anderson, Edward A.
supporting information, p. 12627 - 12639 (2015/09/01)
Bromoenynamides represent precursors to a diversity of azacycles by a cascade sequence of carbopalladation followed by cross-coupling/electrocyclization, or reduction processes. Full details of our investigations into intramolecular ynamide carbopalladation are disclosed, which include the first examples of carbopalladation/cross-coupling reactions using potassium organotrifluoroborate salts; and an understanding of factors influencing the success of these processes, including ring size, and the nature of the coupling partner. Additional mechanistic observations are reported, such as the isolation of triene intermediates for electrocyclization. A variety of hetero-Diels-Alder reactions using the product heterocycles are also described, which provide insight into Diels-Alder regioselectivity.
Process for producing propargyl bromide
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Page 3, (2008/06/13)
This invention provides a process of producing propargyl bromide in the absence of abase. The process comprises: A) bringing together in a reaction zone under an inert atmosphere and in the absence of a base and in the presence of an inert diluent, a feed of phosphorus tribromide and a separate feed of propargyl alcohol thereby forming a reaction mixture; B) while mechanically agitating the mixture being formed in A), maintaining the temperature of the mixture in the range of about 0° C. to about 25° C. to form a product mixture, and then C) raising the temperature of the product mixture to a temperature in the range of about 40° C. to about 60° C. while stirring the product mixture for a ride period of at least about 2.5 hours. Such process can be conducted as a batch process, as a semi-batch process, or as a continuous process.
