Anti-Markovnikov N−H and O−H Additions to Electron-Deficient Olefins Catalyzed by Well-Defined Cu(I) Anilido, Ethoxide, and Phenoxide Systems

Abstract

The monomeric Cu(I) complexes (IPr)Cu(Z) (IPr = 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene, Z = NHPh, OEt, or OPh) react with YH (Y = PhNH, PhCH2NH, EtO, or PhO) to catalytically add Y-H bonds across the C=C bond of electron-deficient olefins to yield anti-Markovnikov organic products. Catalytic activity has been observed for olefins CH2C(H)(X) with X = CN, C(O)Me, or CO2Me as well as crotononitrile. Preliminary studies implicate an intermediate in which the C-Y bond forms through a nucleophilic addition pathway.

Transition‐Metal‐Catalyzed Hydroamination Reactions

“…Key contributions in the development of late transition metal catalysts toward alkene hydroamination, which precede the 2008 comprehensive review [10], focus on contributions using group 9 and 10 metals. Preferred substrates for these transformations include aminoalkenes [230] for intramolecular reactivity or the use of activated alkenes such as styrene [93,109,113,245] or alkenes substituted with electron-withdrawing substituents to generate hydroamination products via aza-Michael-type reactions [246][247][248][249]. Au has also been applied to the hydrofunctionalization of alkenes, although these reactions have demanded the use of protected amine substrates such as ureas [250], tosylamides [251], and carbamates [252].…”

Stabile cyclische Carbene und verwandte Spezies jenseits der Diaminocarbene

“…[217] Im klaren Unterschied dazu beobachtet man im Fall der CBAs eine h 1 -Koordination an Rhodium und Iridium. [197,204] [219] berichten aber auch über eine Zersetzung des Katalysators, die höhere Umsätze verhindert.…”

Reactivity of Ruthenium(II) and Copper(I) Complexes that Possess Anionic Heteroatomic Ligands: Synthetic Exploitation of Nucleophilicity and Basicity of Amido, Hydroxo, Alkoxo, and Aryloxo Ligands for the Activation of Substrates that Possess Polar Bonds as well as Nonpolar C–H and H–H Bonds

“…[155] The phenyl substituent of 1 is also oriented for π-overlap with the amido lone pair (see Figure 4 below Similar to the preparation of Cu-methyl complexes by Sadighi et al, [156] we have employed NHC (NHC = Nheterocyclic carbene) ligands to stabilize monomeric twocoordinate Cu I systems with anionic heteroatomic ligands. [23,25,38] The NHC ligand has been varied between IMes {1,3-bis-(2,4,6-trimethylphenyl)imidazol-2-ylidene}, IPr {1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene}, and SIPr {1,3-bis(2,6-diisopropylphenyl)imidazolin-2-ylidene}. (2) studies suggest that the reaction involves the initial coordination of aniline followed by protonation of the methyl ligand.…”

“…[38] Subsequent proton transfer yields a new copper amido complex and reaction with aniline (presumably via coordination to Cu) yields a free organic product and regenerates the original Cu system (Scheme 33). The hydroalkoxylation reactions are proposed to proceed through a similar mechanism with the exception that product formation likely originates from the zwitterionic intermediate or a linkage isomer Cualkyl complex.…”

“…[23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38] From the perspective of catalyst development, the positioning of a nucleophilic/basic heteroat-omic ligand adjacent to a Lewis acidic metal center provides opportunities for the coordination and activation of external organic substrates toward controlled bond-breaking and bond-forming reactions (Scheme 2). From a fundamental perspective, we have been studying the impact of metal identity, ancillary ligand identity, and the heteroatomic ligand identity and substituents on reactivity.…”