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We have developed a new radical-mediated alkoxypolyhaloalkylation of styrenes with polychloroalkanes and alcohols for the facile synthesis of complex polyhaloalkanes. 4-Methoxybenzenediazonium tetrafluoroborate is a good radical initiator for this transformation. This protocol is well applied to the late-stage functionalization of complex molecules, including vitamin E, estrone and cholesterol derivatives. [ABSTRACT FROM AUTHOR]

We have developed a new oxidative decarboxylation of cinnamic acids with 4-alkyl-1,4-dihydropyridines to construct C(sp3)–C(sp2) bonds in the presence of copper catalyst and dicumyl peroxide (DCP). A variety of internal alkenes have been obtained with mild conditions, broad substrate scope and excellent functional group tolerance. This method has significant potential for application by using inexpensive and stable cinnamic acids instead of alkenyl halides and nitro-olefins. [ABSTRACT FROM AUTHOR]

A new external oxidant-free electrochemical dehydrogenative cross-coupling of xanthenes and ketones for the preparation of functionalized 9-alkyl-9H-xanthenes was developed. This method enables the formation of a new C(sp3)–C(sp3) bond through release of H2 as the major byproduct at room temperature, and features mild conditions, high atom economy, excellent functional-group tolerance, scalability and facile applications in pharmaceutical chemistry. [ABSTRACT FROM AUTHOR]

We here describe a new, selective indium-promoted silver-mediated intermolecular oxidative 1,4-alkylarylation of 1,3-dienes with α-carbonyl alkyl bromides and N-heterocycles for producing functionalized N-heterocycles, which is characterized by its exquisitely controllable regio-/stereo-selectivity and excellent tolerance of functional groups. Mechanistically, the formation of the carbonyl-coordinated η3-allyl-In complex radical intermediate is the key factor for successfully achieving regio- and stereo-selectivity toward 1,4-difunctionalization and (E)-isomers. [ABSTRACT FROM AUTHOR]

The In(OTf)3-promoted three-component photoredox alkylarylation of styrenes with alkyl NHP esters and arenes to access alkylated arene derivatives through C–C bond cleavage and C–H functionalization is reported. By utilizing visible-light photoredox catalysis, alkyl N-hydroxyphthalimide esters serving as alkyl carbon-centered radicals and a wide range of arenes (e.g., indoles, pyrrole, and electron-rich arenes) as nucleophiles were used to enable the introduction of various alkyl groups and aryl groups across the C＝C bonds with excellent selectivity and functional group tolerance. [ABSTRACT FROM AUTHOR]

A new, general silver-catalyzed oxidative 1,2-alkyletherification of unactivated olefinic ketones with primary, secondary and tertiary α-bromoalkyl carbonyls promoted by tert-butyl hydroperoxide (TBHP) and Et3N has been developed. Through the cooperative action of Ag2O, TBHP and Et3N, the reaction enables the construction of highly valuable quaternary-carbon-possessing 2,3-dihydrofuran frameworks using a concomitant intramolecular annulation strategy. [ABSTRACT FROM AUTHOR]

A new, practical directed anodic C–H sulfonylation of N,N-disubstituted anilines with sodium sulfinates for producing o- or p-amino arylsulfones and diarylsulfones is described. Employing the anodic strategy, the reaction proceeds efficiently under mild (room temperature) and transition-metal- and chemical oxidant-free conditions, and enables the formation of C–S bonds via directed activation of ortho- or para-C–H bond to the amino group with broad substrate scope and excellent site selectivity. [ABSTRACT FROM AUTHOR]

A highly para-selective amination of anilines with phenothiazines for producing various functionalized 10-aryl-10H-phenothiazines is reported. The oxidative amination reaction proceeds electrochemically at room temperature, thereby avoiding the use of metals and oxidizing reagents with excellent functional group tolerance and broad substrate scope. [ABSTRACT FROM AUTHOR]

A new copper-catalyzed three-component oxidative 1,2-trifluoromethylarylation of styrenes with NaSO2CF3 and indoles involving aryl C–H bond functionalization is described. This reaction is initiated by single electron transfer upon utilizing TBPB as an oxidant, thus enabling introduction of a CF3 group and an aryl group into the C=C bond of alkenes in a single step. This method represents a highly atom and step-economical access to various CF3-substituted 1,1-diarylalkane derivatives in moderate to good yields with good functional group compatibility. [ABSTRACT FROM AUTHOR]

A new ruthenium(ii)-catalyzed electrooxidative [4+2] annulation of primary benzylic alcohols with internal alkynes is described, which enables benzylic alcohols as weakly directing group precursors to access isocoumarins via multiple C–H functionalization. The reaction works well with a broad substrate scope, tolerates a wide range of functional groups, and incorporates practically the isocoumarin unit into diverse bioactive molecules. Mechanistic studies indicate that activation of aryl C(sp2)–H bonds is achieved through the generation of the active benzoyloxy–Ru(ii) intermediates via oxidation of benzylic alcohols using an electrooxidative Ru(ii) catalyst. [ABSTRACT FROM AUTHOR]

A new copper-catalyzed oxidative three-component intermolecular 1,2-alkylarylation of styrenes with ethers and indoles is disclosed. This method utilizes TBPB as an oxidant to efficiently construct C(sp3)–C(sp3) and C(sp3)–C(sp2) bonds in one step through probable radical and electrophilic alkylation processes, respectively, and a variety of functional groups are well tolerated. [ABSTRACT FROM AUTHOR]

For straightforward access to various substituted 1,1-diarylalkanes a photoredox-catalyzed and copper-promoted 1,2-alkylarylation reaction of styrenes has been developed, which uses α-carbonyl alkyl bromides and N,N-disubstituted anilines as functionalization reagents. In this radical difunctionalization reaction, α-carbonyl alkyl bromides, including primary-, secondary- and tertiary-α-bromoalkyl ketone esters, malonic esters and cycloalkane were transformed to the corresponding 1,1-diarylalkanes in moderate to good yields at room temperature. Notably, this transformation provided a new route for the C–H alkylation of N,N-disubstituted anilines with high para-selectivity beyond the typical Friedel–Crafts alkylation. [ABSTRACT FROM AUTHOR]

An indium-promoted intermolecular oxidative 1,2-alkylarylation of alkenes with alkyl nitriles and N-heteroarenes enabled by C(sp3)–H/C(sp2)–H functionalization is presented. This oxidative radical strategy allows the formation of two new C–C bonds through transformations of two different C–H bonds across the alkenes in a controlled single-step manner, and offers a general, highly atom-economic route for the production of new functionalized N-heteroarenes, including indoles, pyrrolo[2,3-b]pyridine, pyrrolo[3,2,1-ij]quinolone and pyrroles. [ABSTRACT FROM AUTHOR]

A copper-catalyzed oxidative radical strategy to avoid the use of the highly expensive noble metal/ligand catalytic systems is described, which allows selective activation of dual chemical bonds around the Si-atom center relying on the nature of alkylsilanes. While for tertiary silanes selective functionalization of Si–H/silyl C(sp3)–H bonds in intermolecular oxidative annulation cascades with N-(2-(ethynyl)aryl)acrylamides toward silino[3,4-c]quinolin-5(3H)-ones, when using secondary silanes and HSi(TMS)3, dual Si–H bonds or Si–H/Si–Si bonds are selectively cleaved leading to 4H-silolo[3,4-c]quinolin-4-ones. [ABSTRACT FROM AUTHOR]

A Mn-promoted intermolecular oxidative radical heteroannulation of N-(2-cyanoaryl)-acrylamides and tertiary silanes has been described, which provides an efficient route to produce silicon/nitrogen heterocycles, sila-analogues of the known carbon-based structural motifs prevalent in bioactive natural products, pharmaceuticals and materials. The reaction enables Si-incorporation by controlling accurately several chemical bond cleavage and formation processes. Moreover, this reaction represents a new one-step construction of 1,3-azasiline-fused quinolinones that was achieved via silyl C(sp3)–H functionalization using an oxidative radical strategy. [ABSTRACT FROM AUTHOR]

A new palladium-catalyzed dearomatizative [2 + 2 + 1] carboannulation of 1,7-enynes with aryl diazonium salts and H2O is presented. The reaction enables the construction of spirocyclohexadienone-fused cyclopenta[c]quinolin-4(5H)-ones through a sequence of Heck-type addition, 6-exo-dig cyclization, ipso-cyclization, dearomatization and hydrolysis. [ABSTRACT FROM AUTHOR]

A new divergent intermolecular cascade annulation reaction of N-(arylsulfonyl)acrylamides with dual alkyl C(sp3)–H bonds for producing two types of five-membered rings, indanes and pyrrolidin-2-ones, is described. By using cycloalkanes and common alkanes as a one-carbon unit, an intermolecular [4+1] cascade carboannulation of N-(arylsulfonyl)acrylamides was achieved via a sequence of three C–H bond functionalization/aryl migration/desulfonylation that enables the formation of three C–C bonds and one N–H bond. When the one-carbon unit was changed to cycloalkyl ethers, the alternative intermolecular [4+1] cascade heteroannulation reaction occurred and allowed the construction of two C–C bonds and one C–N bond through dual C–H bond functionalization, aryl migration and desulfonylation cascades. [ABSTRACT FROM AUTHOR]

A novel copper-promoted [2+2+2] annulation of 1,n-enynes with azobis(alkyl nitrile)s and H2O for the synthesis of diverse 7,8-dihydrophenanthridine-6,9(5H,6aH)-diones and fluorene is described. The reaction proceeds via the decomposition of azobis(alkyl nitrile)s into the cyanoalkyl radicals as the two-carbon units and offers a new efficient tool for the one-step formation of four new chemical bonds. [ABSTRACT FROM AUTHOR]

The Cu-catalyzed oxidative [2+2+1] annulation of 1,n-enynes (n = 6, 7) with α-carbonyl alkyl bromides through C–Br/C–H functionalization has been developed. Using Ag2CO3/tert-butyl hydroperoxide (TBHP) as co-oxidants, α-carbonyl alkyl bromides provide two bonds, the α-C(sp3)–Br bonds and the α-C(sp3)–H bonds, to cyclize with the 1,n-enynes and Cu(MeCN)4PF6, thus forming three new C–C bonds and two rings in a single reaction. [ABSTRACT FROM AUTHOR]

A Cu-catalyzed oxidative ipso-annulation of activated alkynes with unactivated alkanes for the synthesis of 3-alkyl spiro[4,5]trienones is described. This method allows the formation of two carbon–carbon bonds and one carbon–oxygen bond in a single reaction through a sequence of C–H oxidative coupling, ipso-carbocyclization and dearomatization. [ABSTRACT FROM AUTHOR]

A new metal-free tert-butyl hydroperoxide (TBHP)-mediated carbonyl C(sp2)–H oxidative alkynylation of aldehydes with ethynyl benziodoxolones (EBX) for the synthesis of ynones is described. This method is based on a carbonyl C(sp2)–H oxidative radical coupling process according to mechanistic studies, and provides a general route to the assembly of diverse ynones with a broad substrate scope and excellent functional-group compatibility. [ABSTRACT FROM AUTHOR]

A new Rh(iii)-catalyzed oxidative bicyclization through C–H functionalization is presented. This reaction allows the selective assembly of diverse benzo[g]indoles from 4-arylbut-3-yn-1-amines and internal alkynes via a sequence of aromatic C(sp2)–H functionalization, cyclodimerization and nucleophilic cyclization. [ABSTRACT FROM AUTHOR]

We here describe a new palladium-catalyzed oxidative 6-exo-trig cyclization of 1,6-enynes at room temperature using tBuONO as an oxidant for the synthesis of 3-bicyclo[4.1.0]heptan-5-ones. This cascade strategy involves the hydration, cyclization and cyclopropanation sequence, and represents a new transition-metal-catalyzed oxidative cyclization of 1,6-enynes in a 6-exo-trig fashion. [ABSTRACT FROM AUTHOR]

A new copper-catalyzed oxidative difunctionalization of enol ethers with α-amino carbonyl compounds and hydroperoxides is developed. This method is experimentally simple while allowing for regioselective access to 2-amino-3,4-dioxy carbonyl compounds in good yields, and represents the first example of alkene oxyalkylation through C(sp3)–H functionalization. [ABSTRACT FROM AUTHOR]

We here describe a new copper-catalyzed oxidative coupling of acids with alkanes for the selective synthesis of allylic esters and alkylalkenes. This method achieves multiple dehydrogenation and esterification, representing a new unactivated C(sp3)–H oxidative esterification of acids with common alkanes. [ABSTRACT FROM AUTHOR]

DTBP (di-tert-butyl peroxide) is utilized to mediate oxidative 1,2-difunctionalization of activated alkenes with an aryl C(sp2)–H bond and a benzylic C(sp3)–H bond for the synthesis of functionalized oxindoles. This reaction is a new organomediated strategy for alkene difunctionalization facilitated by Lewis acids. [ABSTRACT FROM AUTHOR]

Palladium-catalyzed annulations of arynes with 2-(2-iodophenoxy)-1-substituted ethanones for the synthesis of 6H-benzo[c]chromenes are presented. This mild route allows formation of two new carbon–carbon bonds viaan α-arylation/annulation process. [ABSTRACT FROM AUTHOR]

We have developed a new radical-mediated alkoxypolyhaloalkylation of styrenes with polychloroalkanes and alcohols for the facile synthesis of complex polyhaloalkanes. 4-Methoxybenzenediazonium tetrafluoroborate is a good radical initiator for this transformation. This protocol is well applied to the late-stage functionalization of complex molecules, including vitamin E, estrone and cholesterol derivatives.

A copper-catalyzed C-H [3 + 2] annulation of N-substituted anilines with α-carbonyl alkyl bromides for the synthesis of 3,3'-disubstituted oxindoles is developed. Tandem C-H cycloamidation reactions of various α-carbonyl alkyl bromide derivatives including tertiary-α-bromoalkyl ketone esters, malonic esters and cycloalkanes, with N-aryl or alkyl substituted anilines, can be performed using this system, affording a vast array of valuable 3,3'-disubstituted oxindoles in moderate to good yields.

A new silver-mediated 1,2-alkylesterification of alkenes with nitriles and acids promoted by a catalytic amount of nickel catalyst for producing acyloxylated nitriles has been developed via a C(sp 3 )-H functionalization process. By employing the NiI 2 and Ag 2 CO 3 catalytic systems, the method features broad substrate scope with respect to carboxylic acids, including linear alkyl acids, cyclic acids, aryl acids and amino acids.

A new copper-catalyzed three-component oxidative 1,2-trifluoromethylarylation of styrenes with NaSO2CF3 and indoles involving aryl C-H bond functionalization is described. This reaction is initiated by single electron transfer upon utilizing TBPB as an oxidant, thus enabling introduction of a CF3 group and an aryl group into the C[double bond, length as m-dash]C bond of alkenes in a single step. This method represents a highly atom and step-economical access to various CF3-substituted 1,1-diarylalkane derivatives in moderate to good yields with good functional group compatibility.

For straightforward access to various substituted 1,1-diarylalkanes a photoredox-catalyzed and copper-promoted 1,2-alkylarylation reaction of styrenes has been developed, which uses α-carbonyl alkyl bromides and N,N-disubstituted anilines as functionalization reagents. In this radical difunctionalization reaction, α-carbonyl alkyl bromides, including primary-, secondary- and tertiary-α-bromoalkyl ketone esters, malonic esters and cycloalkane were transformed to the corresponding 1,1-diarylalkanes in moderate to good yields at room temperature. Notably, this transformation provided a new route for the C-H alkylation of N,N-disubstituted anilines with high para-selectivity beyond the typical Friedel-Crafts alkylation.

A Mn-promoted intermolecular oxidative radical heteroannulation of N-(2-cyanoaryl)-acrylamides and tertiary silanes has been described, which provides an efficient route to produce silicon/nitrogen heterocycles, sila-analogues of the known carbon-based structural motifs prevalent in bioactive natural products, pharmaceuticals and materials. The reaction enables Si-incorporation by controlling accurately several chemical bond cleavage and formation processes. Moreover, this reaction represents a new one-step construction of 1,3-azasiline-fused quinolinones that was achieved via silyl C(sp 3 )-H functionalization using an oxidative radical strategy.

A new palladium-catalyzed dearomatizative [2 + 2 + 1] carboannulation of 1,7-enynes with aryl diazonium salts and H 2 O is presented. The reaction enables the construction of spirocyclohexadienone-fused cyclopenta[c]quinolin-4(5H)-ones through a sequence of Heck-type addition, 6-exo-dig cyclization, ipso-cyclization, dearomatization and hydrolysis.

A new divergent intermolecular cascade annulation reaction of N-(arylsulfonyl)acrylamides with dual alkyl C(sp 3 )-H bonds for producing two types of five-membered rings, indanes and pyrrolidin-2-ones, is described. By using cycloalkanes and common alkanes as a one-carbon unit, an intermolecular [4+1] cascade carboannulation of N-(arylsulfonyl)acrylamides was achieved via a sequence of three C-H bond functionalization/aryl migration/desulfonylation that enables the formation of three C-C bonds and one N-H bond. When the one-carbon unit was changed to cycloalkyl ethers, the alternative intermolecular [4+1] cascade heteroannulation reaction occurred and allowed the construction of two C-C bonds and one C-N bond through dual C-H bond functionalization, aryl migration and desulfonylation cascades.

A new metal-free oxidative decarbonylative [2 + 2 + 2] carbocyclization of N -(2-ethynylaryl)acrylamides with tertiary and secondary alkyl aldehydes is described. This reaction enables the formation of three new C-C bonds in a single reaction by a sequence of oxidative decarbonylation, radical addition across C-C unsaturated bonds, C-H functionalization and annulation, and represents the first oxidative decarbonylative [2 + 2 + 2] carbocyclization approach using tertiary and secondary alkyl aldehydes as a two carbon unit for assembling six-membered carbocycle-fused polycycles.

A new metal-free tert-butyl hydroperoxide (TBHP)-mediated carbonyl C(sp(2))-H oxidative alkynylation of aldehydes with ethynyl benziodoxolones (EBX) for the synthesis of ynones is described. This method is based on a carbonyl C(sp(2))-H oxidative radical coupling process according to mechanistic studies, and provides a general route to the assembly of diverse ynones with a broad substrate scope and excellent functional-group compatibility.

We here describe a new copper-catalyzed oxidative coupling of acids with alkanes for the selective synthesis of allylic esters and alkylalkenes. This method achieves multiple dehydrogenation and esterification, representing a new unactivated C(sp(3))-H oxidative esterification of acids with common alkanes.

A Ni-mediated oxidative C(sp(3))-H functionalization of N,N-substituted amides with α,α-diaryl allylic alcohols through a radical 1,2-aryl migration process has been developed. This process features a broad substrate scope and excellent functional group tolerance. Notably, γ-amino ketones containing an all-carbon quaternary center were synthesized under these conditions in moderate to good yields.

A step-economical method for the cascade cyclization of 1,7-enynes with aromatic sulfonyl chlorides by using a low-cost and more abundant Cu catalyst is presented. This method allows access to benzo[j]phenanthridin-6(5H)-ones and represents a new Cu-catalyzed cascade cyclization of 1,n-enynes.

A new oxidative coupling of unactivated terminal alkenes with amides using peroxides is described, in which mono- and difunctionalization of alkenes are selectively achieved. In this reaction with amides, the chemoselectivity toward the functionalization of the C(sp(3))-H bonds adjacent to the nitrogen atom or the functionalization of the carbonyl C(sp(2))-H bonds across alkenes relies on the reaction conditions.

A novel route to Δ(2)-isoxazolines is presented via silver-mediated radical cyclization of α-halo ketoximes with 1,3-dicarbonyl compounds. This method is performed using a radical strategy, and represents a new example of silver-initiated generation of oxime radicals for the formation of the C(sp(3))-O bonds.

DTBP (di-tert-butyl peroxide) is utilized to mediate oxidative 1,2-difunctionalization of activated alkenes with an aryl C(sp(2))-H bond and a benzylic C(sp(3))-H bond for the synthesis of functionalized oxindoles. This reaction is a new organomediated strategy for alkene difunctionalization facilitated by Lewis acids.

The first example of Ru-catalyzed intramolecular annulation of alkynes with amides via formyl translocation has been developed, which provides an efficient approach for the synthesis of 1H-indole-3-carbaldehydes., (This journal is © The Royal Society of Chemistry 2012)

A new palladium-catalyzed C-H bond activation-annulation-amination tandem method was presented for selectively synthesizing 3-(aminomethylene)-2-oxoindolines. In the presence of Pd(dba)(2), xantphos (L8), AgOAc and Na(2)CO(3), a variety of 3-chloro-2-iodo-N-arylacrylamides underwent the reaction with amides or amines to afford the corresponding 3-(aminomethylene)-2-oxoindolines in moderate to good yields.