Cerium(IV) based oxidative free radical cyclization of active methylene compounds with some cyclic alkenes: A useful annulation method for terpene functionalization
Sign Up to like & getrecommendations! Published in 2019 at "Tetrahedron"
DOI: 10.1016/j.tet.2019.03.039
Abstract: Abstract Ceric ammonium nitrate-mediated oxidative cyclizations of CH-acids with terpenes and terpene like substrates were investigated. Dimedone, acetylacetone, and methyl nitroacetate were condensed with pinene, norbornene, nopol, camphene, and carvone and the reaction stereoselectivity was… read more here.
Keywords: free radical; radical cyclization; annulation; cerium based ... See more keywords
Directed Copper-Catalyzed Tandem Radical Cyclization Reaction of Alkyl Bromides and Unactivated Olefins.
Sign Up to like & getrecommendations! Published in 2022 at "Organic letters"
DOI: 10.1021/acs.orglett.2c00835
Abstract: The free radical cyclization reaction is a promising strategy for ring framework formation. Herein, we report a copper-catalyzed tandem radical cyclization strategy for preparing substituted lactam derivatives. This reaction proceeds through a radical coupling approach,… read more here.
Keywords: copper catalyzed; cyclization; radical cyclization; cyclization reaction ... See more keywords
Polar-Radical Cyclization Cascades with Magnesiated Nitriles.
Sign Up to like & getrecommendations! Published in 2023 at "Organic letters"
DOI: 10.1021/acs.orglett.3c01094
Abstract: Naphthalene converts magnesiated ω-alkenylnitriles into bi- and tricyclic ketones via a polar-radical addition-cyclization cascade. One-electron oxidation of magnesiated nitriles generates nitrile-stabilized radicals that cyclize onto a pendant olefin and then rebound onto the nitrile through… read more here.
Keywords: polar radical; radical cyclization; cyclization; cascades magnesiated ... See more keywords
Sequential Oxidative and Reductive Radical Cyclization Approach toward Asperparaline C and Synthesis of Its 8-Oxo Analogue.
Sign Up to like & getrecommendations! Published in 2017 at "Organic letters"
DOI: 10.1021/acs.orglett.7b00187
Abstract: The most advanced approach, so far, to the asperparalines is developed. Consecutive oxidative and reductive radical cyclizations serve as the key steps to stereoselectively access the complex fully elaborated skeleton containing the cyclopentane and spiro-succinimide… read more here.
Keywords: sequential oxidative; cyclization approach; radical cyclization; reductive radical ... See more keywords
Cobalt-Catalyzed Tandem Radical Cyclization/C-C Coupling Initiated by Directed C-H Activation.
Sign Up to like & getrecommendations! Published in 2019 at "Organic letters"
DOI: 10.1021/acs.orglett.9b01846
Abstract: A cobalt-N-heterocyclic carbene catalyst promotes a tandem radical cyclization/C-C coupling reaction between tosylamide-tethered bromo-alkenes and aryl N-H imines initiated by chelation-assisted arene C-H activation, affording 3-(arylmethyl)pyrrolidine derivatives in moderate to good yields. The reaction tolerates… read more here.
Keywords: tandem radical; radical cyclization; cobalt catalyzed; activation ... See more keywords
Aroylchlorination of 1,6-Dienes via a Photoredox Catalytic Atom-Transfer Radical Cyclization Process.
Sign Up to like & getrecommendations! Published in 2019 at "Organic letters"
DOI: 10.1021/acs.orglett.9b03222
Abstract: A method using aroyl chlorides as atom-transfer radical cyclization agents in a novel visible-light photocatalytic aroylchlorination reaction is developed. The overall transformation involves the formation of two new C-C bonds and one new C-Cl bond… read more here.
Keywords: atom transfer; radical cyclization; transfer radical; aroylchlorination dienes ... See more keywords
Switchable Regioselective 6-endo or 5-exo Radical Cyclization via Photoredox Catalysis.
Sign Up to like & getrecommendations! Published in 2022 at "Journal of the American Chemical Society"
DOI: 10.1021/jacs.2c00192
Abstract: Controlling the regioselectivity of radical cyclizations to favor the 6-endo mode over its kinetically preferred 5-exo counterpart is difficult without introducing substrate prefunctionalization. To address this challenge, we have developed a simple method for reagent… read more here.
Keywords: catalysis; radical cyclization; endo exo; product ... See more keywords
Enantioselective Radical Cyclization for Construction of 5-Membered Ring Structures by Metalloradical C-H Alkylation.
Sign Up to like & getrecommendations! Published in 2018 at "Journal of the American Chemical Society"
DOI: 10.1021/jacs.8b01662
Abstract: Radical cyclization represents a powerful strategy for construction of ring structures. Traditional radical cyclization, which is based on radical addition as the key step, necessitates the use of unsaturated substrates. Guided by the concept of… read more here.
Keywords: ring structures; construction; radical cyclization; enantioselective radical ... See more keywords
Photocatalytic radical cyclization of α-halo hydrazones with β-ketocarbonyls: facile access to substituted dihydropyrazoles.
Sign Up to like & getrecommendations! Published in 2017 at "Chemical communications"
DOI: 10.1039/c7cc01470h
Abstract: A mild and efficient method for the photocatalytic radical cyclization of α-halo hydrazones with β-ketocarbonyls has been described. This strategy provides a potential protocol for the construction of functionalized 4,5-dihydropyrazoles in moderate to high yields. read more here.
Keywords: halo hydrazones; radical cyclization; hydrazones ketocarbonyls; cyclization halo ... See more keywords
Copper-catalyzed radical 1,2-cyclization of indoles with arylsulfonyl hydrazides: access to 2-thiolated 3H-pyrrolo[1,2-a]indoles
Sign Up to like & getrecommendations! Published in 2017 at "Organic chemistry frontiers"
DOI: 10.1039/c7qo00478h
Abstract: A copper-catalyzed cascade radical 1,2-cyclization of indoles with arylsulfonyl hydrazides was developed, affording a series of 2-thiolated 3H-pyrrolo[1,2-a]indoles in moderate to excellent yields. This transformation proceeded with sequential radical addition to a triple bond and… read more here.
Keywords: cyclization indoles; indoles arylsulfonyl; radical cyclization; cyclization ... See more keywords
Intramolecular radical cyclization approach to access highly substituted indolines and 2,3-dihydrobenzofurans under visible-light
Sign Up to like & getrecommendations! Published in 2018 at "RSC Advances"
DOI: 10.1039/c8ra01787e
Abstract: The combination of visible-light and tris(trimethylsilyl)silane promoting intramolecular reductive cyclization protocol for the synthesis of functionalized indolines and 2,3-dihydrobenzofurans has been developed. The transformations occur in the absence of transition metal and additional photocatalyst. In… read more here.
Keywords: indolines dihydrobenzofurans; cyclization approach; radical cyclization; visible light ... See more keywords