1206-41-3Relevant articles and documents
Harnessing Energy-Transfer in N-Centered Radical-Mediated Synthesis of Pyrrolidines
Fodran, Peter,Wallentin, Carl-Johan
, p. 3213 - 3218 (2020)
Atom transfer radical addition (ATRA), cyclization (ATRC), and polymerization (ATRP) are valuable synthetic methods for the functionalization of olefins. With the advent of photoredox catalysis, visible-light became a popular tool for the initiation of these reactions. We have developed a protocol that enables easy access to distally functionalized pyrrolidines employing blue-light mediated atom transfer radical [3+2] cyclization. The reaction is scalable, proceeds at very mild conditions. tolerates various functional groups, and provides the corresponding products in good to excellent yields. If rigid olefins are utilized as the reaction partners, the products can be isolated as single diastereomers. The mechanistic investigations provide strong support for an energy-transfer mechanism.
Alkene: Versus alkyne reactivity in unactivated 1,6-enynes: Regio-And chemoselective radical cyclization with chalcogens under metal-And oxidant-free conditions
Kudale, Vishal Suresh,Li, Jing,Mutra, Mohana Reddy,Tsai, Wu-Hsun,Wang, Jeh-Jeng
supporting information, p. 2288 - 2300 (2020/04/21)
Herein, we have developed metal and oxidant-free visible light-promoted alkene vs. alkyne regio-And chemoselective radical cascade cyclization of electronically unbiased 1,6-enynes with chalcogens to synthesize substituted pyrrolidines bearing chalcogens. The reaction generated three new bonds, namely, C-SO2, C-C, and C-Se under extremely mild conditions. Furthermore, we achieved regio-And chemoselective mono-addition of aromatic thiophenols with unactivated 1,6-enynes. The key features of this protocol are broad substrate scope, environment-friendly conditions, operational simplicity, atom economy, and amenability to gram-scale synthesis. The mechanistic studies corroborate that the reaction proceeds via a radical pathway.
Formal Bromine Atom Transfer Radical Addition of Nonactivated Bromoalkanes Using Photoredox Gold Catalysis
Zidan, Montserrat,McCallum, Terry,Swann, Rowan,Barriault, Louis
supporting information, p. 8401 - 8406 (2020/11/03)
Organic transformations mediated by photoredox catalysis have been at the forefront of reaction discovery. Recently, it has been demonstrated that binuclear Au(I) bisphosphine complexes, such as [Au2(μ-dppm)2]X2, are capable of mediating electron transfer to nonactivated bromoalkanes for the generation of a variety of alkyl radicals. The transfer reactions of bromine, derived from nonactivated bromoalkanes, are largely unknown. Therefore, we propose that unique metal-based mechanistic pathways are at play, as this binuclear gold catalyst has been known to produce Au(III) Lewis acid intermediates. The scope and proposed mechanistic overview for the formal bromine atom transfer reaction of nonactivated bromoalkanes mediated by photoredox Au(I) catalysis is presented. The methodology presented afforded good yields and a broad scope which include examples using bromoalkanes and iodoarenes.
Gold-Catalyzed Enantioselective Intramolecular Annulation of Ene-Yne-Carbonyls via Benzopyrylium-Type Intermediates
Koshikawa, Takumi,Satoh, Masakazu,Masutomi, Koji,Shibata, Yu,Tanaka, Ken
supporting information, p. 1488 - 1492 (2019/01/04)
It has been established that a cationic gold(I)/(R)-H8-binap complex catalyzes the enantioselective intramolecular [4+2] annulation of benzene-linked ene-yne-carbonyls via benzopyrylium-type intermediates at room temperature to give chiral tric
Unprecedented nucleophile-promoted 1,7-S or Se shift reactions under Pummerer reaction conditions of 4-alkenyl-3-sulfinylmethylpyrroles
Go, Takashi,Morimatsu, Akane,Wasada, Hiroaki,Tanabe, Genzoh,Muraoka, Osamu,Sawada, Yoshiharu,Yoshimatsu, Mitsuhiro
, p. 2722 - 2729 (2018/11/21)
A unique 1,7-S- and Se-shift reaction under Pummerer reaction conditions of 4-alkenyl-3-sulfinyl- and seleninylpyrroles was described. The usual Pummerer reaction of 4-(alkenylaminomethyl)-3-phenylsulfinylpyrroles and a successive reaction with tetrabutyl
Nickel(0)-Catalyzed N-Allylation of Amides and p-Toluenesulfonamide with Allylic Alcohols under Neat and Neutral Conditions
Azizi, Mohamed Salah,Edder, Youssef,Karim, Abdallah,Sauthier, Mathieu
, p. 3796 - 3803 (2016/08/16)
Nickel(0)-catalyzed direct N-allylation of amides and p-toluenesulfonamide with allylic alcohols took place in the presence of Ni0–diphosphine complexes. The corresponding N-allylated (and/or N,N-diallylated) products were obtained in moderate to high yields under neutral conditions.
Lewis acid mediated intramolecular C-C bond formation of alkyne-epoxide leading to six-membered nitrogen and oxygen heterocycles
Ghosh, Priya,Saha, Pipas,Bondalapati, Somasekhar,Indukuri, Kiran,Saikia, Anil K.
, p. 4119 - 4124 (2014/05/20)
Intramolecular C-C bond formation of oxygen- and nitrogen-tethered alkynes and epoxide mediated by Lewis acid under ambient conditions is described. A simple procedure for the synthesis of 3,6- and 5,6-dihydropyrans and 3,4-dehydropiperidines from acyclic
Cyclobutene formation in PtCl2-catalyzed cycloisomerizations of heteroatom-tethered 1,6-enynes
Ni, Zhenjie,Giordano, Laurent,Tenaglia, Alphonse
, p. 11703 - 11706 (2014/10/15)
Aza(oxa)bicyclo[3.2.0]heptenes are accessed through the PtCl 2-catalyzed cycloisomerizations of heteroatom-tethered 1,6-enynes featuring a terminal alkyne and amide as the solvent. It is shown that the weak coordinating properties of the solven
Synthesis of 3-aza-bicyclo[3.1.0]hexan-2-one derivatives via gold-catalyzed oxidative cyclopropanation of N -allylynamides
Wang, Kai-Bing,Ran, Rui-Qiao,Xiu, Shi-Dong,Li, Chuan-Ying
supporting information, p. 2374 - 2377 (2013/06/27)
N-Allylynamides with various functional groups and different substitution patterns can be converted into 3-aza-bicyclo[3.1.0]hexan-2-one derivatives in moderate to high yield using IMesAuCl/AgBF4 as the catalyst and pyridine N-oxide as the oxidant. A noncarbene mediated approach is proposed as the mechanism.
Rhodium(iii)-catalyzed oxidative olefination of N-allyl sulfonamides
Hu, Shui,Wang, Dongqi,Liu, Jiexiang,Li, Xingwei
supporting information, p. 2761 - 2765 (2013/05/08)
Rhodium(iii)-catalyzed oxidative couplings between N-sulfonyl allylamines and activated olefins have been achieved. Only olefination occurred for acrylates, and the butadiene product can be further cyclized under palladium-catalyzed aerobic conditions. The coupling with N,N-dimethylacrylamide followed a cyclization pathway.
