115085-24-0Relevant articles and documents
Asymmetric dihydroxylation of disubstituted allenes
Fleming, Steven A.,Liu, Renmao,Redd, J. Ty
, p. 8095 - 8098 (2005)
Asymmetric dihydroxylation of 1,1-disubstituted and 1,3-disubstituted allenes can be used to synthesize chiral α-hydroxy ketones. We have also obtained α,α′-dihydroxy ketones with high enantioselectivity from 1,3-disubstituted allenes. Low conversion of the dihydroxylation of chiral allenes can be used as a kinetic resolution of sterically hindered allenes.
Straightforward Stereoselective Synthesis of Seven-Membered Oxa-Bridged Rings through in Situ Generated Cycloheptenol Derivatives
Wang, Mengdan,Yin, Liqiang,Cheng, Lu,Yang, Yajie,Li, Yanzhong
, p. 12956 - 12963 (2021/09/13)
An iodine-mediated stereoselective synthesis of seven-membered oxa-bridged rings via in situ generated cycloheptenols was reported. This process was realized through the combination of C-C σ-bond cleavage and C-O bond-forming reactions in a one-pot fashion from simple and easily accessible raw materials. The formation of carbon radicals initiated by I2 was the key to the reaction.
Gold-Catalyzed Regioselective Synthesis of Pyrazolo[1,4]oxazepines via Intramolecular 7-endo-dig Cyclization
Doddi, Venkata Ramana,Karunakar, Galla V.,Purnachandar, Dalovai,Raju, Chittala Emmaniel,Sreenivasulu, Gottam,Thummala, Yadagiri
supporting information, (2020/06/30)
An efficient gold-catalyzed intramolecular regioselective synthesis of pyrazolo[1,4]oxazepines were developed from alkynyl-substituted pyrazoles via 7-endo dig cyclization. In this reaction a new C–N bond was formed and substituted pyrazolo[1,4]oxazepines
A Grignard-type phase-vanishing method: Generation of organomagnesium reagent and its subsequent addition to carbonyl compounds
Matsubara, Hiroshi,Niwa, Yuki,Matake, Ryosuke
, p. 1276 - 1280 (2015/06/02)
Abstract A quadraphasic phase-vanishing system comprised of diethyl ether, magnesium, perfluoropolyether, and iodoalkane efficiently generated the corresponding Grignard reagents, which subsequently added to carbonyl compounds in the ether layer to afford alkylated alcohols in good yields.
Kinetic or Dynamic Control on a Bifurcating Potential Energy Surface? An Experimental and DFT Study of Gold-Catalyzed Ring Expansion and Spirocyclization of 2-Propargyl-β-tetrahydrocarbolines
Zhang, Lei,Wang, Yi,Yao, Zhu-Jun,Wang, Shaozhong,Yu, Zhi-Xiang
, p. 13290 - 13300 (2015/11/09)
In classical transition state theory, a transition state is connected to its reactant(s) and product(s). Recently, chemists found that reaction pathways may bifurcate after a transition state, leading to two or more sets of products. The product distribution for such a reaction containing a bifurcating potential energy surface (bPES) is usually determined by the shape of the bPES and dynamic factors. However, if the bPES leads to two intermediates (other than two products), which then undergo further transformations to give different final products, what factors control the selectivity is still not fully examined. This missing link in transition state theory is founded in the present study. Aiming to develop new methods for the synthesis of azocinoindole derivatives, we found that 2-propargyl-β-tetrahydrocarbolines can undergo ring expansion and spirocyclization under gold catalysis. DFT study revealed that the reaction starts with the intramolecular cyclization of the gold-activated 2-propargyl-β-tetrahydrocarboline with a bPES. The cyclization intermediates can not only interconvert into each other via a [1,5]-alkenyl shift, but also undergo ring expansion (through fragmentation/protodeauration mechanism) or spirocyclization (through deprotonation/protodeauration mechanism). Detailed analysis of the complex PESs for substrates with different substituents indicated that the reaction selectivity is under dynamic control if the interconversion of the intermediates is slower than the ring expansion and spirocyclization processes. Otherwise, the chemical outcome is under typical kinetic control and determined by the relative preference of ring expansion versus spirocyclization pathways. The present study may enrich chemist's understanding of the determinants for selectivities on bPESs.
Direct synthesis of 4-fluoroisoxazoles through gold-catalyzed cascade cyclization-fluorination of 2-alkynone O-methyl oximes
Jeong, Yunkyung,Kim, Bom-I,Lee, Jae Kyun,Ryu, Jae-Sang
, p. 6444 - 6455 (2014/08/05)
A tandem protocol for the synthesis of fluorinated isoxazoles has been developed via catalytic intramolecular cyclizations of 2-alkynone O-methyl oximes and ensuing fluorination. The reactions proceed smoothly at room temperature in the presence of 5 mol
One-pot synthesis of 3,5-disubstituted isoxazoles from propargylic alcohols through propargylic N-hydroxylamines
Raji Reddy, Chada,Vijaykumar, Jonnalagadda,Jithender, Enukonda,Reddy, Gangireddy Pavan Kumar,Gree, Rene
, p. 5767 - 5773 (2012/11/07)
An efficient approach has been described for the synthesis of 3,5-disubstituted isoxazoles from propargylic alcohols. The strategy involves a one-pot p-TSA-catalyzed N-propargylation of protected hydroxylamines followed by a TBAF-mediated detosylative 5-endo-dig cyclization. The method was successfully used for the synthesis of various 3,5-disubstituted isoxazoles.
Highly enantioselective addition of linear alkyl alkynes to aromatic aldehydes
Du, Xi,Wang, Qin,He, Xiao,Peng, Rui-Guang,Zhang, Xiao,Yu, Xiao-Qi
experimental part, p. 1142 - 1146 (2011/10/08)
An asymmetric linear alkyl alkyne addition to aromatic aldehydes catalyzed by the Ti-(R)-BINOL system is reported with high enantioselectivity and yield. Our study expands upon the synthetic scope of propargylic alcohols, which could serve as potentially useful intermediates for the synthesis of various natural products.
Chemoselective addition of in situ prepared lithium alkynyl borates to aldehydes: a practical and transition metal free approach toward the synthesis of propargylic alcohols
Francesco, Irene Notar,Renier, Antoine,Wagner, Alain,Colobert, Fran?oise
experimental part, p. 1386 - 1389 (2010/04/25)
A convenient synthesis of functionalized propargylic alcohols arising from the 1,2-addition of lithium alkynyl-trimethyl borate onto aldehydes under transition metal free mild conditions is reported. The reaction tolerates a wide range of functional groups, is highly chemoselective and the propargylic alcohols are isolated in good to excellent yields.
New application of n-halosuccinimide/PPh3 for the halogenation of propargyl alcohols to haloallenes
Du, Xin,Dai, Yao,He, Ren,Lu, Shirong,Bao, Ming
experimental part, p. 3940 - 3949 (2010/03/25)
An efficient and convenient new method has been developed for the preparation of haloallenes from propargyl alcohols by a reagent combination of N-halosuccinimide and triphenylphosphine. Chloroallenes 2 and bromoallenes 3 were obtained exclusively in mode
