16666-78-7Relevant academic research and scientific papers
Synthesis of 2- and 17-substituted estrone analogs and their antiproliferative structure-activity relationships compared to 2-methoxyestradiol
Shah, Jamshed H.,Agoston, Gregory E.,Suwandi, Lita,Hunsucker, Kimberly,Pribluda, Victor,Zhan, Xiaoguo H.,Swartz, Glenn M.,LaVallee, Theresa M.,Treston, Anthony M.
, p. 7344 - 7352 (2009)
A novel series of 17-modified and 2,17-modified analogs of 2-methoxyestradiol (2ME2) were synthesized and characterized. These analogs were designed to retain or potentiate the biological activities of 2ME2 and have diminished metabolic liability. The ana
A general strategy for the stereocontrolled preparation of diverse 8- and 9-membered Laurencia -type bromoethers
Snyder, Scott A.,Treitler, Daniel S.,Brucks, Alexandria P.,Sattler, Wesley
, p. 15898 - 15901 (2011)
A unique procedure to effect a ring-expanding bromoetherification process is described, wherein tetrahydrofurans and tetrahydropyrans are smoothly transformed into 8- and 9-membered bromoethers in a regio- and stereocontrolled manner through the use of BDSB (bromodiethylsulfonium bromopentachloroantimonate). These products resemble the cores of the Laurencia C15 acetogenins. In light of the generality and effectiveness of the approach, this work provides a unique strategy for their laboratory preparation and may implicate a possible biosynthesis pathway.
Heavier Carbonyl Olefination: The Sila-Wittig Reaction
Reiter, Dominik,Frisch, Philipp,Szilvási, Tibor,Inoue, Shigeyoshi
supporting information, p. 16991 - 16996 (2019/10/16)
The Wittig reaction is one of the most versatile tools in the repertoire of organic chemists. Thus, a broad variety of carbonyl compounds can be converted to tailor-made alkenes with phosphorus ylides under mild conditions. However, no comparable reaction has been reported for silanones, the silicon congeners of ketones. Here, we demonstrate for the first time the successful application of the Wittig olefination to iminosilylsilanone 1. The selective formation of a series of silenes (R2Sia? CR2) via the sila-Wittig reaction revealed an unprecedented approach to otherwise elusive compounds. In addition, the highly reactive and zwitterionic nature of 1 was also susceptible to nucleophilic attacks and cycloaddition reactions by and with the phosphorus ylides. Our results therefore make another important contribution to discovering the differences and similarities between carbon and silicon.
Enantioselective palladium-catalyzed addition of malonates to 3,3-difluoropropenes
Drouin, Myriam,Paquin, Jean-Fran?ois
, p. 6023 - 6032 (2018/09/11)
Monofluoroalkenes bearing a malonate unit at the β position can be synthesized by the enantioselective addition of diesters to 3,3-difluoropropenes. The difference in reactivity regarding the geometry and the substituents of the alkene of the 3,3-difluoropropenes, as well as the alkyl groups of the malonates, was studied and limitations were identified. The reaction was also performed with different 3,3-difluoropropenes. Further synthetic transformations of a newly functionalized monofluoroalkene were also accomplished.
Synthetic and Spectroscopic Investigations Enabled by Modular Synthesis of Molecular Phosphaalkyne Precursors
Transue, Wesley J.,Yang, Junyu,Nava, Matthew,Sergeyev, Ivan V.,Barnum, Timothy J.,McCarthy, Michael C.,Cummins, Christopher C.
supporting information, p. 17985 - 17991 (2019/01/09)
A series of dibenzo-7-phosphanorbornadiene compounds, Ph3PC(R)PA (1-R; A = C14H10, anthracene; R = Me, Et, iPr, sBu), are reported to be capable of thermal fragmentation to generate alkyl-substituted phosphaalkynes (RC≡P) concomitant with triphenylphosphine and anthracene. Facile preparation of these molecular precursors proceeds by treatment of ClPA with the appropriate ylide Ph3P=CHR (2 equiv). For methyl, ethyl, and isopropyl substituents, the phosphaalkyne conversions are measured to be 56-73% in solution by quantitative 31P NMR spectroscopy. In the case of compound 1-Me, the kinetic profile of its spontaneous unimolecular fragmentation is investigated by an Eyring analysis. The resulting 1-phosphapropyne is directly detected by solution NMR spectroscopy and gas phase rotational microwave spectroscopy. The latter technique allows for the first time measurement of the phosphorus-31 nuclear spin-rotation coupling tensor. The nuclear spin-rotation coupling provides a link between rotational and NMR spectroscopies, and is contextualized in relation to the chemical shift anisotropy.
Olefin metathesis based approach to diversely functionalized pyrrolizidines and indolizidines; total synthesis of (+)-monomorine
Lesma, Giordano,Colombo, Alessia,Sacchetti, Alessandro,Silvani, Alessandra
experimental part, p. 590 - 596 (2009/06/20)
New scaffolds for the stereoselective synthesis of diversely functionalized chiral enantiopure indolizidines and pyrrolidines were synthesized from the cross and ring-closing metathesis reactions of appropriate intermediates, readily available from L-pyroglutamic acid. The versatility of this strategy was demonstrated by the synthesis of an indolizidine-based azasugar analogue and of the natural alkaloid (+)-monomorine.
Synthesis of (+)-coronafacic acid
Taber, Douglass F.,Sheth, Ritesh B.,Tian, Weiwei
supporting information; experimental part, p. 2433 - 2437 (2009/07/25)
An enantioselective synthesis of (+)-coronafacic acid has been achieved. Rhodium-catalyzed cyclization of an a-diazoester provided the intermediate cyclopentanone in high enantiomeric purity. Subsequent Fe-mediated cyclocarbonylation of a derived alkenyl
A new catalytic Cu(II)/sparteine oxidant system for β,β-phenolic couplings of styrenyl phenols: Synthesis of carpanone and unnatural analogs
Daniels, R. Nathan,Fadeyi, Olugbeminiyi O.,Lindsley, Craig W.
supporting information; experimental part, p. 4097 - 4100 (2009/05/30)
(Chemical Equation Presented) A new catalytic Cu(ll)/sparteine system has been developed to promote β,β-phenolic couplings of styrenyl phenols en route to carpanone and related unnatural congeners in yields exceeding 85%.
Total synthesis of (-)-histrionicotoxin 285A and (-)- perhydrohistrionicotoxin
Macdonald, James M.,Horsley, Helen T.,Ryan, John H.,Saubern, Simon,Holmes, Andrew B.
supporting information; experimental part, p. 4227 - 4229 (2009/06/06)
(Chemical Equation Presented) Starting from commercially available (S)-glycidol, and via a common intermediate, the total synthesis of (-)-histrionicotoxin 285A and (-)-perhydrohistrionicotoxin has been achieved. Key to this synthesis was the efficient co
Novel synthesis of α-galactosyl-ceramides and confirmation of their powerful NKT cell agonist activity
Lee, Adrianne,Farrand, Kathryn J.,Dickgreber, Nina,Hayman, Colin M.,Juers, Stefan,Hermans, Ian F.,Painter, Gavin F.
, p. 2785 - 2798 (2007/10/03)
α-Galactosyl-ceramide (1) has been identified as a powerful modulator of immunological processes through its capacity to bind CD1d molecules and specifically activate invariant natural killer (NK)-like T cells (iNKT cells). This paper describes the synthe
