Palladium-catalysed anti-Markovnikov selective oxidative amination

Abstract

In recent years the synthesis of amines and other nitrogen containing motifs has been a major area of research in organic chemistry due to their being widely represented in biologically active molecules. Current strategies rely on a multistep approach and require one reactant to be activated prior to the carbon-nitrogen bond formation. This leads to reaction inefficiency and functional group intolerance. As such, a general approach to the synthesis of nitrogen-containing compounds from readily available and benign starting materials is highly desirable. Here we present a Pd-catalyzed oxidative amination reaction, where the addition of the nitrogen occurs at the less substituted carbon of a double bond, in what is known as anti-Markovnikov selectivity. Alkenes are shown to react with imides in the presence of a palladate catalyst to generate the terminal imide via trans-aminopalladation. Subsequently, olefin isomerization occurs to afford the thermodynamically favored products. Both the scope of the transformation and mechanistic investigations are reported.

Efficient access to unprotected primary amines by iron-catalyzed aminochlorination of alkenes

“…A complementary and potentially more versatile alternative would use ubiquitous alkenes, which are commonly encountered in petrochemical feedstocks and synthetic intermediates, as starting materials (7). Although aminofunctionalization reactions, such as hydroamination (8)(9)(10)(11)(12)(13) and aminohydroxylation (14)(15)(16)(17) of alkenes and alkene azidation (18)(19)(20)(21), have played an important role in this area, these reactions are generally limited by the need to protect (and later deprotect) the nitrogen, ac-tivate the olefin with an aryl substituent, or generate hazardous azide intermediates (Fig. 1A).…”

Palladium‐Catalyzed Oxidation Reactions of Alkenes with Green Oxidants

“… Conversion of allyl moieties by the groups of a) Stahl [from Refs. (top) and (bottom)], b) Grubbs, c) Bäckvall, d) Hull, and e) White . TFA=trifluoroacetate, NMP= N ‐methyl‐2‐pyrrolidone, BQ=1,4‐benzoquinone, pc=phthalocyanine, DHBQ=2,5‐dihydroxy‐1,4‐benzoquinone.…”

“…The well-known Ts uji-Trost reactioni sapowerful strategy for the transformation of allyl moieties; however,t he prefunc-tionalization of substrates limits its application.M oreover,c ontrol of the selectivity during palladium-catalyzed oxidative functionalization of allyl moieties remains ac hallenging research topic. [40] For the use of O 2 in the conversiono fa llyl moieties, the groupso fS tahl, [41] Grubbs, [42] Bäckvall, [43] Hull, [44] and White [45] have performed much groundbreaking work (Scheme 27). Since 2014, we have also successively developed as eries of aerobico xidative allylic CÀHf unctionalizations of alkenes, withO 2 as the sole oxidant participating in the cycle (Scheme 28).…”

“…Conversion of allyl moieties by the groups of a) Stahl [from Refs. [41a] (top) and [41b] (bottom)],b)Grubbs,[42] c) Bäckvall,[43] d) Hull,[44] and e) White [45]. TFA = trifluoroacetate, NMP = N-methyl-2-pyrrolidone,B Q= 1,4-benzoquinone, pc = phthalocyanine, DHBQ = 2,5-dihydroxy-1,4-benzoquinone.ChemSusChem 2019ChemSusChem , 12,2911ChemSusChem -2935 www.chemsuschem.org 2019 Wiley-VCH Verlag GmbH &Co. KGaA, Weinheim…”

Nickel-catalyzed remote and proximal Wacker-type oxidation

“…Indeed, there were few clues in the literature implying the exceptional difficulty for the development of this protocol [22][23][24][25][26][27][28][29][30][31][32][33] . For example, isomerization of olefinic alcohols enabled by transition-metal hydride species leads to the ketone products, which requires migration of the olefinic unsaturations toward the tethered alcohols [22][23][24][25][26][27][28][29] . Alternatively, internal olefins isomerization/hydroborations or isomerization/ hydrosilylations followed by oxidations can realize remote oxidations [30][31][32][33][34] .…”