6214-31-9Relevant academic research and scientific papers
1-HALOCYCLOPROPENES AND PROPARGYLIC HALIDES FROM THE REACTION OF TRIHALOCYCLOPROPANES WITH METHYL LITHIUM
Baird, Mark S.,Nethercott, William
, p. 605 - 608 (1983)
1,1,2-Trihalocyclopropanes (halogen=chlorine or bromine) undergo 1,2-dehalogenation on reaction with methyl lithium, and in a number of cases the product is a 1-halocyclopropene.In the reactions of (20, X=Br, Cl) and (25) a rearrangement occurs even at low temperatures and propargylic halides are isolated, while (16) is converted to 2-chlorocyclohex-2-enylidene which may be trapped by furan.
Total synthesis of (+)-frondosin A. Application of the RU-catalyzed [5+2] cycloaddition
Trost, Barry M.,Hu, Yimin,Horne, Daniel B.
, p. 11781 - 11790 (2007)
The first total synthesis of (+)-frondosin A was accomplished in 19 longest linear and 21 total steps from commercially available materials. The key features of the synthesis include a Ru-catalyzed [5+2] cycloaddition, a Claisen rearrangement, and a ring expansion to construct the core of the frondosin A in a diastereoselective and regioselective fashion. This is the first application of a Ru-catalyzed [5+2] cycloaddition in the total synthesis of a natural product. Through this synthesis, the absolute configuration of (+)-frondosin A was established.
Double-diels-alder approach to maoecrystal V. unexpected C-C bond-forming fragmentations of the [2.2.2]-bicyclic core
Smith, Brandon R.,Njardarson, Jon T.
supporting information, p. 5316 - 5319 (2017/11/07)
Synthetic studies toward maoecrystal V are reported. An oxidative dearomatization/Diels-Alder cascade to assemble the natural product carbocyclic core in one step is proposed. A facile electrocyclization is shown to suppress the intramolecular allene Diel
Silver-Catalyzed Three-Component 1,1-Aminoacylation of Homopropargylamines: α-Additions for Both Terminal Alkynes and Isocyanides
Tong, Shuo,Piemontesi, Cyril,Wang, Qian,Wang, Mei-Xiang,Zhu, Jieping
supporting information, p. 7958 - 7962 (2017/06/27)
The reaction of secondary homopropargylamines, isocyanides, and water in the presence of a catalytic amount of silver acetate and subsequent purification by chromatography on silica gel afforded substituted proline amides in good to excellent yields. Primary homopropargylamines underwent a cyclizative Ugi–Joullié three-component reaction with isocyanides and carboxylic acids to afford functionalized N-acyl proline amides. High diastereoselectivity was observed in the synthesis of 4-alkoxy and 4,5-disubstituted proline derivatives. This work represents the first examples of a three-component cyclizative 1,1-aminoacylation of terminal alkynes.
Ruthenium-Catalyzed Hydroalkynylative Cyclization of 1,6-Enynes Induced by Substituent Effects
Liu, Rui,Ni, Zhenjie,Giordano, Laurent,Tenaglia, Alphonse
supporting information, p. 4040 - 4043 (2016/08/30)
The ruthenium-catalyzed 1,6-enyne cyclization in the presence of bulky substituted terminal alkyne proceeds smoothly at room temperature to afford highly substituted five-membered cyclic compounds featuring a 1,5-enyne motif. Deuterium-labeling experiment
Total synthesis of bryostatins: The development of methodology for the atom-economic and stereoselective synthesis of the ring C subunit
Trost, Barry M.,Frontier, Alison J.,Thiel, Oliver R.,Yang, Hanbiao,Dong, Guangbin
scheme or table, p. 9762 - 9776 (2011/10/05)
Bryostatins, a family of structurally complicated macrolides, exhibit an exceptional range of biological activities. The limited availability and structural complexity of these molecules makes development of an efficient total synthesis particularly impor
Palladium(0) catalyzed regioselective carbonyl propargylation across tetragonal tin(II) oxide via redox transmetallation
Banerjee, Moloy,Roy, Sujit
, p. 534 - 535 (2007/10/03)
Facile homopropargylation of aldehydes by propargyl bromides over tetragonal tin(II)oxide and catalytic palladium(0) occurs which is proposed to involve the prior formation of dinuclear allenylpalladium followed by redox transmetallation to β-SnO.
A McMurry route to the dienediyne portion of models of the neocarzinostatin chromophore
Rank, Elisabeth,Brueckner, Reinhard
, p. 1045 - 1053 (2007/10/03)
The 6-ring/10-ring dienediyne model 11 of the antitumor agent neocarzinostatin chromophore 1 and its 6-ring/11-ring homolog 12 have been obtained in 41 and 18% yields, respectively, by McMurry cyclizations of ketoaldehydes 8 and 9 using TiCl3·2DME and Zn/Cu couple. Compounds 8 and 9 were obtained by rnultistep syntheses starting from the readily available acetylenic aldehydes HC=CC(CH3)2-(CH2)nCH=O (18, n = 1, 21, n = 2). Dienediyne 11 was converted into the dienediyne ketone 33 which cycloaromatized at room temperature giving the octahydrophenanthrone 35 in 16% yield.
The Preparation and Lithiation of 1-Halogenocyclopropenes
Baird, Mark S.,Hussain, Helmi H.,Nethercott, William
, p. 1845 - 1854 (2007/10/02)
Reaction of a range of 1,1,2-trihalogenocyclopropanes (halogen = bromine, chlorine) with methyl-lithium in ether at -90 - 20 deg C leads to 1,2-dehalogenation to the corresponding 1-halogenocyclopropene.The halogenocyclopropenes are readily lithiated by lithium-halogen exchange with a second equivalent of methyl-lithium to give 1-lithiocyclopropenes, which are in turn trapped by electrophiles; an exception to this is compound (21; X = Cl), which leads to 3-methylbuta-1,2-dienylidene (31) by initial lithium-hydrogen exchange and loss of lithium chloride.The cyclopropenes (5; R = Me, X = Br or Cl) and (21; X = Br or Cl) decompose even at temperatures around ambient, leading either to enynes (6; R = Me) or halogenoalkynes (18; X = Br or Cl).A 12C-labelling study indicates that C-1 of the cyclopropene (21; X = Cl) becomes C-2 of the alkyne (18; X = Cl) on rearrangement.
