Enantioselective Pd-Catalyzed Allylation Reaction of Fluorinated Silyl Enol Ethers

Enantioselective construction of quaternary N-heterocycles by palladium-catalysed decarboxylative allylic alkylation of lactams

“…Over the past seven years, our laboratory has reported an array of methods for the synthesis of α-quaternary ketones xx,xxi,xxii,xxiii and demonstrated the use of these methods in a number of complex molecule syntheses. xxiv,xxv,xxvi,xxvii Concurrent to our efforts, the Trost lab xxviii,xxix,xxx,xxxi,xxxii and others xxxiii,xxxiv,xxxv,xxxvi have developed a series or related allylic alkylation methods. In the course of our investigations of the ketone enolate allylic alkylation and other alkylation processes, we have often encountered interesting ligand electronic effects and, in certain cases, pronounced solvent effects.…”

Michael Addition Catalyzed by Chiral Secondary Amine Phosphoramide Using Fluorinated Silyl Enol Ethers: Formation of Quaternary Carbon Stereocenters

“…The necessity of using them for developing catalytic asymmetric reactions is justified by the finding that deprotonative activation of the corresponding α‐fluorinated ketones are unexpectedly difficult 8b,c. While they have found utility in catalytic asymmetric allylic substitution,16 Mannich,17 and aldol reactions,8b–d none of them led to enantioselective creation of quaternary carbon atoms, a formidable task in organic chemistry 18. To meet this challenge, along with our efforts in asymmetric synthesis of quaternary oxindoles,19 we tried the catalyst C1 in the MM addition of the difluoroenoxysilane 1 a to the isatylidene malononitrile 2 a ,20a–c the asymmetric version of which is undeveloped (Scheme ) 9a.…”

Enantioselective Palladium‐Catalyzed Decarboxylative Allylation of Carbazolones: Total Synthesis of (−)‐Aspidospermidine and (+)‐Kopsihainanine A

“…Recently, transition‐metal‐catalyzed asymmetric decarboxylative allylation has emerged as a powerful transformation in organic synthesis,5–7 chiefly because of the pioneering efforts of the groups of Stoltz,6a,b Tunge,6f Trost,6h–i Nakamura,6l Murakami,6m You,6t and others 6n–u. While a series of different types of substrates, including cyclic ketones, vinylogous thioesters, and lactams (Scheme ), have been employed successfully in this transformation, there is no report on the catalytic enantioselective decarboxylative allylic alkylation of heterocyclic carbazolones.…”