56253-66-8Relevant academic research and scientific papers
Stille reactions catalytic in tin: A "Sn-F" route for intermolecular and intramolecular couplings
Gallagher, William P.,Maleczka Jr., Robert E.
, p. 841 - 846 (2007/10/03)
(Chemical Equation Presented) Polymethylhydrosiloxane (PMHS) made hypercoordinate by KF(aq) allows Me3SnH to be recycled during a Pd(0)-catalyzed hydrostannation/Stille cascade. Starting with a variety of alkynes, in situ vinyltin formation is followed by Stille reaction with aryl, styryl, benzyl, or vinyl electrophiles present in the reaction mixture. Both inter- and intramolecular versions of the process are possible with tin loads of approximately 6 mol %. Regeneration of the organotin hydride is believed to proceed through a Me3SnF intermediate. Given the aggregated nature of organotin fluorides and the ability to use these organotins in substoichiometric quantities, the hazards and purification problems associated with the removal of organotin wastes from reaction mixtures are minimized.
Stille couplings catalytic in tin: The "Sn-O" approach
Gallagher,Terstiege,Maleczka Jr.
, p. 3194 - 3204 (2007/10/03)
A one-pot tandem Pd-catalyzed hydrostannylation/Stille coupling protocol for the stereoselective generation of vinyltins and their subsequent union, employing only catalytic amounts of tin, is described. By recycling the organotin halide Stille byproduct back to organotin hydride, a hydrostannylation/cross-coupling sequence can be carried out with catalytic amounts of tin. Such a process is most effective with Me3SnCl serving as the tin source. This protocol allows a 94% reduction of the tin requirement, while maintaining good yields (up to 90%) for a variety of Stille products. Furthermore, since one cycle requires the tin to undergo at least four transformations, each moiety of trialkyltin is experiencing a minimum of 60 reactions over the course of the hydrostannylation/Stille, sequence.
Stille couplings catalytic in tin: a "Sn-F" approach.
Maleczka Jr.,Gallagher
, p. 4173 - 4176 (2007/10/03)
A new tin recycling method for Stille couplings catalytic in tin is reported. PMHS made hypercoordinate by KF((aq)) allows Me(3)SnH to be efficiently recycled during a Pd(0)-catalyzed hydrostannation/Stille cascade. Relative to previously disclosed protoc
Microwave-assisted one-pot hydrostannylation/Stille couplings.
Maleczka Jr.,Lavis,Clark,Gallagher
, p. 3655 - 3658 (2007/10/03)
In a fraction of the time required by conventional methods, microwave-accelerated one-pot hydrostannylation/Stille coupling allows 1-alkynes to be efficiently transformed into 1,3-dienes or styrenes.
Cyclialkylation of arylalkyl epoxides with solid acid catalysts
Elings, Jacob A.,Downing, Roger S.,Sheldon, Roger A.
, p. 837 - 846 (2007/10/03)
Solid acids, such as zeolites and clays, catalyse the intramolecular hydroxyalkylation (cyclialkylation) of several arylalkyl epoxides in moderate to excellent conversions and selectivities. The use of solid acids in these cyclialkylations provides a cleaner, better alternative to conventional Lewis and Bronsted acids, enabling a more facile workup of reaction mixtures and, in several cases, better selectivities.
A Convenient Method for the Transformation of Allylstannanes to Alcohols, Ethers, Esters, and Amines
Takeda, Takeshi,Inoue, Tomoya,Fujiwara, Tooru
, p. 985 - 988 (2007/10/02)
Allylstannanes were easily oxidized with copper(II) bromide in the presence of water, alcohols, and sodium acetate to give the corresponding allylic alcohols, ethers, and acetates, respectively.The allylic amines were also obtained by the succesive treatm
