Selective N Functionalization of Methane and Ethane to Aminated Derivatives by Main-Group-Directed C–H Activation

Abstract

To our knowledge, there is no precedent for the direct conversion of light alkanes to aminated products by CH activation. Previous molecular systems reported for alkane amination operate by radical or nitrene-type reactions which generally result in unintended overfunctionalization. Here we disclose the first examples of direct conversion of methane and ethane to aminated products by C–H activation facilitated by electrophilic, main-group complexes dissolved in N-acids. Alkane conversion products were achieved with selectivities up to >95% and yields up to 65% based on added main-group electrophile. Experimental studies and DFT calculations support a C–H activation mechanism to generate a metal–alkyl intermediate that undergoes N-functionalization.

Tenfold Metalation of Ferrocene: Synthesis, Structures, and Metallophilic Interactions in FeC10(HgX)10

“…Mono‐ and polymercuration of aromatic compounds, [6–11] olefins, [12] as well as alkanes [13, 14] have been observed in reactions involving sources of Hg 2+ . Even unreactive C−H bonds such as methane can be brought to reaction using Hg(NTf 2 ) 2 [14] . However, interest in organomercury chemistry has declined during the past decades due to the high toxicity of organomercury compounds.…”

“…[4] However,i n many cases CÀHa ctivation relies on the presence of directing groups. [5] One of the most activem etals in CÀHa ctivation,a lthoughn owadays widelyi gnored, is mercury.M ono-and polymercuration of aromatic compounds, [6][7][8][9][10][11] olefins, [12] as well as alkanes [13,14] have been observed in reactions involving sources of Hg 2 + .E venu nreactiveC ÀHb onds such as methane can be broughtt or eaction using Hg(NTf 2 ) 2 . [14] However,i nterest in organomercury chemistry has declined during the past decades due to the high toxicity of organomercury compounds.…”

Evidence for Genuine Bimetallic Frustrated Lewis Pair Activation of Dihydrogen with Gold(I)/Platinum(0) Systems

“…Another transition state was located when exploring route 'b', TSH-H, FLP, which corresponds to a truly FLP-type activation, resulting from the lateral attack of the donor Pt atom of 2 to a H2 molecule coordinated in the expected side-on fashion to the acidic (R2Ar'P)Au + fragment. In view of the high energy barriers of the above mechanisms, and considering recent studies highlighting the key role of triflimidate and triflate counteranions in related bond activation processes, 45 we explored the role of NTf2in H-H cleavage. When the counter anion was allowed to interact with the acidic Au center at the transition state, TS'H-H,FLP, the energy barrier decreased by ca.…”

Copper‐Catalyzed Dehydrogenative Amidation of Light Alkanes

“…Crabtree reported the formation of imines from ammonia and methane or ethane by photo‐activated mercury, [6] Guo and Zuo reported the formation of hydrazides by addition of alkyl radicals, formed photochemically by Ce halides, to the N−N bonds of azo compounds, [7] and Ess and Periana reported stoichiometric reactions of organomercury compounds in triflimide solvents (Scheme 1 a ). [8] Most recently, Chang reported the insertion of a nitrene unit, predominantly into the methylene units of alkanes, catalyzed by cobalt complexes. [9] Reaction with the primary C−H bonds of ethane was observed, but the yields were modest, and no reactivity with methane was described (Scheme 1 b ).…”

“…This yield of the product from functionalization of ethane is more than double that of prior catalytic aminations of ethane. [ 6 , 7 , 8 , 9 ]…”