Palladium-catalyzed carbostannylation by means of reagents containing carbon–tin–halogen inter-element linkages

Palladium-Catalyzed, Stereoselective, Cyclizative Alkenylboration of Carbon−Carbon Double Bonds through Activation of a Boron−Chlorine Bond

“…It would be highly attractive if the strategy could be extended to carboboration of carbon−carbon double bonds, which would provide a new synthetic access to stereodefined alkylboronates. It should be noted that carbometalation of alkenes involving boron, silicon, and tin has had only limited success, including uncatalyzed carboboration with triallylborane and catalytic carbostannation of norbornene and norbornadiene . In this report, we describe our findings on palladium-catalyzed cyclizative carboboration of CC bonds using organozirconium reagents as organic group donors.…”

Making and Breaking of Sn−C and In−C Bonds in Situ: The Cases of Allyltins and Allylindiums

“…Allyltrihalostannanes generated in situ using Pd II /SnCl 2 reagent also mediate the carbostannylation of alkenes in onepot. 36 For example, norbornene reacts with allyl chloride in toluene in the presence of catalytic PdCl 2 (PhCN) 2 and SnCl 2 to give allyl(trihalostannyl)norbornane 9a in 97% yield (Scheme 45). The halogen atoms on tin are easily functionalized by subsequent treatment with Grignard reagent.…”

Palladium-catalyzed novel addition–elimination reaction of alkenyltin reagents to norbornene

“…Subsequent norbornene insertion step appears to conform to carbopalladation, instead of stannylpalladation, to generate the key-intermediate A, stereoselectively. In the case of allylstannylation, reductive elimination took place from A to give the carbostannylation product, probably because the intermediate that corresponds to complex A is so labile owing to inefficient coordination by p-bond of the allylic moiety and b-hydride-elimination is not accessible [1,3]. The above mentioned product ratio of the arylstannylation would indicate that its p-system plays an important role in making the insertion of the second norbornene [2 Á/4].…”

“…The reaction of the former reagent afforded a mixture of the product with one norbornene moiety (1) and that with two norbornene moieties (2), while that of the latter gave the adduct with one norbornene, exclusively. The product ratio between 1 and 2 showed a certain level of dependence on electronic character of the aromatic substituent.…”