173074-01-6Relevant academic research and scientific papers
Synthesis of phthalan derivatives via a formal intramolecular 1,3-insertion of rhodium(II) azavinyl carbenes into O[sbnd]Si bond
Deng, Changchang,Duan, Shengguo,Jie, Yuchen,Luo, Huan,Xiang, Qiaoyi,Xu, Ze-Feng
, (2021/08/30)
The first formal intramolecular 1,3-insertion into O[sbnd]Si bond of rhodium(II) azavinyl carbene have been developed, and valuable phthalan derivatives could be synthesized efficiently. In addition, various functional groups could be introduced to the pr
Sodium sulfide in methanol: A two-in-one reagent for deprotection of silyl and formation of propargyl sulfide
Hatial, Ishita,Mukherjee, Raja,Senapati, Kalyan,Basak, Amit
supporting information, p. 4275 - 4279 (2015/06/22)
A new reagent Na2S/MeOH for silyl deprotection has been developed. The reagent has several advantages which include deprotection of C-TMS, O-TMS, O-TBS, and O-TBDPS, selective removal of C-TMS and O-TMS in the presence of O-TBS and simultaneous
Intramolecular C-H activation through gold(I)-catalyzed reaction of iodoalkynes
Morn-Poladura, Pablo,Rubio, Eduardo,Gonzlez, Jos M.
, p. 3052 - 3055 (2015/04/14)
The cycloisomerization reaction of 1-(iodoethynyl)-2-(1-methoxyalkyl)arenes and related 2-alkyl-substituted derivatives gives the corresponding 3-iodo-1-substituted-1H-indene under the catalytic influence of IPrAuNTf2 [IPr = 1,3-bis(2,6-diisopropyl)phenylimidazol-2-ylidene; NTf2 = bis(trifluoromethanesulfonyl)imidate]. The reaction takes place in 1,2-dichloroethane at 80°C, and the addition of ttbp (2,4,6-tritert-butylpyrimidine) is beneficial to accomplish this new transformation in high yield. The overall reaction implies initial assembly of an intermediate gold vinylidene upon alkyne activation by gold(I) and a 1,2-iodine-shift. Deuterium labeling and crossover experiments, the magnitude of the recorded kinetic primary isotopic effect, and the results obtained from the reaction of selected stereochemical probes strongly provide support for concerted insertion of the benzylic C-H bond into gold vinylidene as the step responsible for the formation of the new carbon-carbon bond.
Indium-catalyzed annulation of indoles with ethyl (2-ethynylaryl)methyl carbonates: Synthesis and photoluminescent properties of aryl- and heteroaryl[b]carbazoles
Nagase, Yuta,Miyamura, Takuhiro,Inoue, Kensuke,Tsuchimoto, Teruhisa
supporting information, p. 1170 - 1172 (2013/10/22)
Two successive carbon-carbon bond-forming annulation of indoles with ethyl (2-ethynylaryl)methyl carbonates and their heteroaryl analogs under indium catalysis provided aryl- and heteroaryl[b]carbazoles, photoluminescent properties of which were then eval
Rh2(S-PTAD)4-catalyzed asymmetric cyclopropenation of aryl alkynes
Briones, John F.,Davies, Huw M.L.
supporting information; experimental part, p. 4313 - 4317 (2011/07/29)
Rh2(S-PTAD)4 is an effective catalyst for the asymmetric cyclopropenation of aryl alkynes using a siloxyvinyldiazoacetate as the carbenoid precursor. Upon deprotection of the silyl protecting group, highly enantioenriched cyclopropen
Platinum and ruthenium chloride-catalyzed cycloisomerization of 1-alkyl-2-ethynylbenzenes: Interception of π-activated alkynes with a benzylic C-H bond
Tobisu, Mamoru,Nakai, Hiromi,Chatani, Naoto
supporting information; experimental part, p. 5471 - 5475 (2009/12/06)
(Chemical Equation Presented) Air-stable and commercially available alkynophilicmetal salts, such as PtCl2, PtCl4, and [RuCl2(CO)3]2, catalyze the cycloisomerization of 1-alkyl-2-ethynylbenzenes to produce substituted indenes even at an ambient temperature. Electrophilically activated alkynes can be intercepted by simple benzylic C-Hbonds at primary, secondary, and tertiary carbon centers. Mechanistic studies, such as labeling studies and kinetic isotope and substituent effects, indicate that the cycloisomerization proceeds through the formation of a vinylidene intermediate and turnover-limiting 1,5-shift of benzylic hydrogen.
Taxane synthesis through intramolecular pinacol coupling at C-1 - C-2. Highly oxygenated C-aromatic taxanes
Swindell, Charles S.,Fan, Weiming
, p. 1109 - 1118 (2007/10/03)
Chiral, nonracemic intramolecular pinacol coupling substrates 3/20 and 30 have been prepared from ethyl isopropyl ketone and acryloyl chloride, which provide the A-ring and either o-iodobenzyl alcohol or 2,4-dimethoxybenzyl alcohol, which provide the respective aromatic C-rings, in 14-16 linear steps in overall yields of approximately 20%. Potential pinacol coupling substrate 23 could not be made available for investigation due to intervening pinacol rearrangement in the acetonide formation step. 3/20 undergo stereoselective cyclizations mediated by TiCl4-Zn in which the C-9 oxygen substituent plays the dominant role in determining the stereochemical outcome at C-1 and C-2 in the respective tricyclic products 4 and 21. The formation of 21 is the more stereoselective process. The reagent of choice for the transformation of 30 into 31 is SmI2, which, although less stereoselective than TiCl4-Zn, leads to higher yielding carbon-carbon bond formation relative to carbonyl reduction. These pinacol cyclizations are interpreted to occur through endo boat-chair transition structures that prefer to orient the developing C-2 substituent and the preexisting C-9 substituent equatorially. Pinacol product 31 was converted through three additional steps into 40 having a B-ring closely related to that of taxol. We believe that these studies indicate pinacol cyclizations at C-1-C-2 to have considerable potential for producing advanced intermediates for syntheses of taxol and related complex taxanes.
