71804-74-5Relevant academic research and scientific papers
Access to Triazolopiperidine Derivatives via Copper(I)-Catalyzed [3+2] Cycloaddition/Alkenyl C?N Coupling Tandem Reactions
Xiao, Guorong,Wu, Kaifu,Zhou, Wei,Cai, Qian
, p. 4988 - 4991 (2021/10/14)
A copper-catalyzed [3+2] cylcoaddition/ alkenyl C?N coupling tandem reaction was demonstrated. It provided a method for the formation of triazolopiperidine skeletons. (Figure presented.).
Iodo Meyer-Schuster rearrangement of 3-alkoxy-2-yn-1-ols for β-mono (exclusively Z-selective)-/disubstituted α-iodo-α,β-unsaturated esters
Puri, Surendra,Thirupathi, Nuligonda,Reddy, Maddi Sridhar
supporting information, p. 5246 - 5249 (2015/02/19)
We herein present the iodo Meyer-Schuster rearrangement of 3-alkoxypropargyl alcohols for α-iodo-α,β-unsaturated esters using iodine or NIS in dichloromethane at ambient temperature. Substrates prepared from both aldehydes and ketones are found to be equally good feedstock for the reaction to produce β-mono-and-disubstituted products. Irrespective of the substitution, substrates prepared from aldehydes gave Z-isomers exclusively. (Chemical Equation Presented).
Synthesis of angularly fused aromatic compounds from alkenyl enediynes by a tandem radical cyclization process
Roy, Snigdha,Anoop, Anakuthil,Biradha, Kumar,Basak, Amit
supporting information; experimental part, p. 8316 - 8319 (2011/10/09)
Let's get radical: A general synthetic route toward angularly ortho-fused polyaromatic [4]helicenes starting from aryl alkenyl N-substituted cyclic enediynes is described (see scheme; DMSO=dimethyl sulfoxide, Ns=4-nitrobenzenesulfonyl). The process involved a Bergman cyclization (BC) as the key step of an unprecedented tandem radical reaction.
Cyclization of 2-alkynylallyl alcohols to highly substituted furans by gold(I)-carbene complexes
Hashmi, A. Stephen K.,Rudolph, Matthias,Rominger, Frank
, p. 667 - 671 (2011/03/22)
Various 2-alkynylallyl alcohols were synthesized by a generally applicable Sonogashira coupling protocol. Subsequent gold-catalyzed transformation was investigated. The use of AuI catalysts bearing carbene ligands, of either the N-heterocyclic carbene or nitrogen acyclic carbene type, delivered the desired products with low catalyst loadings and under very mild reaction conditions. A broad array of substrates was tested, including alkyl-, alkenyl-, and aryl-substituted alkynes, as well as substrates with two alkynyl moieties. The methodology turned out to have a broad scope. Secondary allyl alcohols were also tolerated, and the resulting trisubstituted furans could be isolated in high yields. Easily accessible 2-alkynylallyl alcohols were transformed into highly substituted furans under very mild reaction conditions by the use of gold(I)-carbene catalysts. A broad range of substrates could be transformed in high yields and within short reaction times.
Synthesis of γ-alkylidene α,β-unsaturated δ-lactones by ring-closing metathesis: Application to the synthesis of the C 1-C8 subunit of Biselide E
Salit, Anne-Frédérique,Barbazanges, Marion,Miege, Frédéric,Larrauf?e, Marie-Hélène,Meyer, Christophe,Cossy, Janine
scheme or table, p. 2583 - 2586 (2009/04/16)
The synthesis of γ-alkylidene α,β-unsaturated δ-lactones was achieved by ring-closing metathesis of acrylates derived from (1,3-butadien-2-y1)methanols. The application to the synthesis of the C1-C8 subunit of biselide E is reported.
Cascade radical synthesis of heteroarenes via iminyl radicals
Bowman,Bridge,Brookes,Cloonan,Leach
, p. 58 - 68 (2007/10/03)
A novel cascade cyclisation protocol has been developed which 'zips up' two rings to form new tetracycles. In the protocol, treatment of vinyl bromides and iodides with hexamethylditin (Me3Sn· yields intermediate vinyl radicals which undergo 5-exo cyclisation onto nitrile groups to yield intermediate iminyl radicals. The iminyl radicals can undergo 6-endo cyclisation (or 5-exo followed by neophyl rearrangement) to yield tetracyclic π-radicals which lose hydrogen (H·) in an H-abstraction step. Methyl radicals, generated from the breakdown of trimethylstannyl radicals (Me3Sn·), are proposed as a possible H-abstractor for this final oxidative step. The protocol has been used to synthesise the tetracyclic rings A-D (tetracycle indolizino[1,2-b]quinolin-9(11H)-one) of the anticancer alkaloids camptothecin, mappicine, nothapodytine B and nothapodytine A. The protocol has also been applied to the synthesis of analogues of camptothecin in which ring A has been replaced by thiophene (8,10-dihydrothieno[2′,3′:5,6]pyrido[2,3-a]indolizin-8-one) and ring D by pyrrole (10H-pyrrolizino[1,2-b]quinoline) and benzene (11H-indeno[1,2-b]quinolin-11-one).
Synthesis of heteroarenes via radical cyclisation onto nitriles
Bowman,Bridge,Cloonan,Leach
, p. 765 - 768 (2007/10/03)
A new protocol for the synthesis of tetracyclic nitrogen heteroarenes using cascade radical cyclisation has been developed. The key steps involve 5-exo vinyl radical cyclisation onto nitriles to yield intermediate iminyl radicals which cyclise onto an arene rings. Rings A-D of the anticancer alkaloids camptothecin, mappicine and nothapodytines A and B have been synthesised using this protocol.
