40637-56-7Relevant articles and documents
Palladium-catalyzed intra-molecular olefin insertion reaction of α-alkenyl-α-acyloxytrialkylsilane. Synthesis of optically active carbocycle
Sakaguchi, Kazuhiko,Okada, Takuya,Yamada, Takeshi,Ohfune, Yasufumi
, p. 3925 - 3928 (2007)
Pd-catalyzed intra-molecular olefin insertion/carbonylation reaction of optically active α-alkenyl-α-acyloxysilanes is described. The reactions proceeded in a stereoselective manner to give five- and six-membered optically active carbocycles having (E)-vinylsilane in their side chains. Under CO condition, optically active carbocycles containing one-carbon homologated side chain were produced by Pd-catalyzed tandem olefin insertion-carbonylation reaction.
Metal-Free Domino Oligocyclization Reactions of Enynals and Enynones with Molecular Oxygen
Abbasi Kejani, Alireza,Khosravi, Hormoz,Rominger, Frank,Balalaie, Saeed,Breit, Bernhard
supporting information, p. 1291 - 1295 (2021/02/20)
A novel metal-free direct addition of molecular oxygen to the C-C triple bond toward benzannulated oxygen-bridged seven-membered ring systems and aza[3.1.0]bicycle skeletons under 3O2 atmosphere has been described. The reaction proceeds through at least three intramolecular C-O and C-C bond forming steps via green, simple, and unprecedented domino radical processes with high selectivity and good yields.
Synthesis of Various Bridged Ring Systems via Rhodium-Catalyzed Bridged (3+2) Cycloadditions
He, Yu-Tao,Hou, Bao-Long,Li, Chuang-Chuang,Li, Li-Xuan,Lin, Xiaohong
supporting information, (2022/01/11)
Here, we describe the rhodium-catalyzed bridged (3+2) cycloaddition cascade reactions of N-sulfonyl-1,2,3-triazoles, which allowed the efficient diastereoselective construction of various functionalized and synthetically challenging bridged ring systems. This simple, direct transformation had a broad substrate scope and excellent functional group tolerance. The highly strained polycyclic bicyclo[2.2.2]octa[b]indole core of fruticosine was synthesized efficiently using this methodology.
Methyl Radical Initiated Kharasch and Related Reactions
Tappin, Nicholas D. C.,Renaud, Philippe
supporting information, p. 275 - 282 (2020/12/07)
An improved procedure to run halogen atom and related chalcogen group transfer radical additions is reported. The procedure relies on the thermal decomposition of di-tert-butylhyponitrite (DTBHN), a safer alternative to the explosive diacetyl peroxide, to produce highly reactive methyl radicals that can initiate the chain process. This mode of initiation generates byproducts that are either gaseous (N2) or volatile (acetone and methyl halide) thereby facilitating greatly product purification by either flash column chromatography or distillation. In addition, remarkably simple and mild reaction conditions (refluxing EtOAc during 30 minutes under normal atmosphere) and a low excess of the radical precursor reagent (2 equivalents) make this protocol particularly attractive for preparative synthetic applications. This initiation procedure has been demonstrated with a broad scope since it works efficiently to add a range of electrophilic radicals generated from iodides, bromides, selenides and xanthates over a range of unactivated terminal alkenes. A diverse set of radical trap substrates exemplifies a broad functional group tolerance. Finally, di-tert-butyl peroxyoxalate (DTBPO) is also demonstrated as alternative source of tert-butoxyl radicals to initiate these reactions under identical conditions which gives gaseous by-products (CO2). (Figure presented.).
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.
Enantioselective α-Amination of Acyclic 1,3-Dicarbonyls Catalyzed by N-Heterocyclic Carbene
Santra, Surojit,Maji, Ujjwal,Guin, Joyram
supporting information, p. 468 - 473 (2020/02/04)
Herein, we describe a method for the catalytic enantioselective α-amination of α-substituted acyclic 1,3-ketoamides and 1,3-amidoesters that affords the products possessing N-substituted quaternary stereocenters with a chiral N-heterocyclic carbene (NHC). The reaction is based on the utilization of an intrinsic Br?nsted base characteristic of NHC that enables the catalytic formation of a chiral ion pair comprising the enolate and the azolium ion. A series of challenging open-chain α-substituted 1,3-dicarbonyls are aminated via this method with ee's of ≤99%.
Copper-Catalyzed Dehydrogenative Diels-Alder Reaction
Jiang, Bing,Liang, Qiu-Ju,Han, Yu,Zhao, Meng,Xu, Yun-He,Loh, Teck-Peng
supporting information, p. 3215 - 3219 (2018/06/11)
A practical and effective copper-catalyzed dehydrogenative Diels-Alder reaction of gem-diesters and ketone with dienes has been established. The active dienophiles were generated in situ via a radical-based dehydrogenation process, which reacted with a wide variety of dienes to afford various polysubstituted cyclohexene derivatives in good to excellent yields.
Annelated Cyclobutanes by Fe-Catalyzed Cycloisomerization of Enyne Acetates
Kramm, Frederik,Teske, Johannes,Ullwer, Franziska,Frey, Wolfgang,Plietker, Bernd
supporting information, p. 13335 - 13338 (2018/09/25)
Cationic Fe complexes of the general type [(Ph3P)2Fe(CO)(NO)]X (X=BF4, BArF4) catalyze the redox-neutral cycloisomerization of 1,6- and 1,7-enyneacetates to afford bicyclic cyclobutanes under mild conditions in good yields and diastereoselectivities.
An improved synthesis of 4-chloro-7H-pyrrolo[2,3-d]pyrimidine
Zhang, Yu-Liu,Xu, Cheng-Tao,Liu, Ting,Zhu, Yong,Luo, Yu
, p. 638 - 642 (2018/08/17)
[Figure not available: see fulltext.] An improved seven-step synthesis of 4-chloro-7H-pyrrolo[2,3-d]pyrimidine from dimethyl malonate with 31% overall yield is described. The procedure is operationally simple and practical for the synthesis of the 4-chloro-7H-pyrrolo[2,3-d]pyrimidine building block.
Design and synthesis of malonamide derivatives as antibiotics against methicillin-resistant staphylococcus aureus
Su, Jung-Chen,Huang, Yu-Ting,Chen, Chang-Shi,Chiu, Hao-Chieh,Shiau, Chung-Wai
, (2018/01/03)
Methicillin-resistant Staphylococcus aureus (MRSA) is a serious threat to humans. Most existing antimicrobial drugs, including the β-lactam and quinoxiline classes, are not effective against MRSA. In this study, we synthesized 24 derivatives of malonamide, a new class of antibacterial agents and potentiators of classic antimicrobials. A derivative that increases bacterial killing and biofilm eradication with low cell toxicity was created.