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α-Trifluoromethyl-styrenes, trifluoromethyl-enynes, and dienes undergo palladium-catalyzed trimethylenemethane cycloadditions under mild reaction conditions. The trifluoromethyl group serves as a unique σ-electron-withdrawing group for the activation of the olefin toward the cycloaddition. This method allows for the formation of exomethylene cyclopentanes bearing a quaternary center substituted by the trifluoromethyl group, compounds of interest for the pharmaceutical, agrochemical, and materials industries. In the diene series, the cycloaddition operates in a [3 + 4] and/or [3 + 2] manner to give rise to seven- and/or five-membered rings. This transformation greatly improves the scope of the TMM cycloaddition technology and provides invaluable insights into the reaction mechanism.

ConspectusRadical allylations represent effective routes to various alkenes, but to date they have relied chiefly on organostannane derivatives and still suffer from significant limitations with respect to the substitution pattern of the starting allylating agent. Indeed, while substituents at the β-position relative to the radical leaving group are well-tolerated, introduction of α-substituents induces a major complication due to the rapid and usually irreversible isomerization of the starting allylating agents. Although a number of research groups have made substantial efforts to develop heavy-metal-free radical allylations, methods compatible with α-substitution of the allylating agent are still scarce. Furthermore, quite a few systems are limited by the relative inaccessibility of the substrates. This Account summarizes our sustained efforts regarding the development of allylic alcohols into “ideal” radical allylating agents and presents published as well as some unpublished results. The systems we ha...

2-Fluoropyridinyl-6-oxy-substituted vinyl sulfides react with xanthate-derived radicals to yield functionalized vinyl sulfides via an addition/elimination process.

An operationally simple reaction sequence for the synthesis of α-keto vinyl carbinols is developed.

Unprotected vinyl carbinols react with the radicals generated from xanthanes involving a rare cleavage of a C—C bond in a non-strained open chain structure.

Title reaction gives zincates that undergo a 1,2-metallate rearrangement along with the transfer of an alkyl or a silyl group affording allenylzinc intermediates.

A wide range of biologically important title compounds is available under these conditions.