A highly regio- and stereo-selective hydrostannation reaction of various fluorine-containing internal acetylene derivatives

On the Hydrostannylation of Aryl Propargylic Alcohols and Their Derivatives: Remarkable Differences in Both Regio‐ and Stereoselectivity in Radical‐ and Nonradical‐Mediated Transformations

“…Interestingly, Z ‐stereochemical outcomes were obtained for the β ‐ vinyltriphenylstannanes 14 b and c . Assuming that the initial tin hydride additions in Table 3 and 4 proceed by a stereospecific syn ‐addition,10 the Z stereochemistries of 14 b and c can only be explained by rapid E to Z ‐isomerization, because any of the β ‐ ( E ) isomer has been never observed, although it remains unclear how this process proceeds in the presumed absence of radicals. No such isomerization was observed with β ‐ vinyltributylstannanes as for those shown in Table 3.…”

“…Likewise, the protodestannylation of β ‐( Z )‐ 8 h with HCl in Et 2 O gave the disubstituted internal alkene ( E )‐16 ( Z / E 2:98) in high recovery. Pd‐catalyzed cross‐crossing of β ‐( Z )‐ 8 h with aryliodide 17 in the presence of CuI co‐catalyst10 gave ( Z )‐ 18 without any isomerization of the double bond. Similarly, the Pd‐catalyzed cross‐coupling of β ‐( Z )‐ 8 h with acid chloride 19 in the presence of CuCN co‐catalyst gave ( Z )‐ 20 as the major isomer.…”

Functionalized fluoroalkyl and alkenyl silanes: Preparations, reactions, and synthetic applications

“…Here again, location of lithium on C-1 in the intermediate 3,3,3-trifluoropropenyllithium is syn to the CF 3 group (Scheme 84) [122]. Hydrostannylation by the addition of stannyl radical to a triple bond of 339 enables a regio-and stereoselective synthesis of (Z)-2-stannyl-3,3,3-trifluoropropenyl(dimethylphenyl)silane 340 [123].…”

Highly stereoselective one-pot synthesis of tetrasubstituted alkenes via carbopalladation reaction of fluorine-containing acetylene derivatives

“…Recently, we have developed highly regio-and stereoselective hydrostannation [5], hydroboration [6], carbocupration [7], and carbostannylation reactions [8] of fluoroalkylated acetylene derivatives 2, which realized the efficient as well as practical approaches to 1 [9]. Herein we wish to describe the practical one-step coupling reaction of three components, such as aryl iodides, fluoroalkylated alkynes, and arylboronic acids, leading to the corresponding tetrasubstituted alkenes stereoselectively.…”