109088-53-1Relevant academic research and scientific papers
Scalable Negishi Coupling between Organozinc Compounds and (Hetero)Aryl Bromides under Aerobic Conditions when using Bulk Water or Deep Eutectic Solvents with no Additional Ligands
Dilauro, Giuseppe,Azzollini, Claudia S.,Vitale, Paola,Salomone, Antonio,Perna, Filippo M.,Capriati, Vito
supporting information, p. 10632 - 10636 (2021/04/09)
Pd-catalyzed Negishi cross-coupling reactions between organozinc compounds and (hetero)aryl bromides have been reported when using bulk water as the reaction medium in the presence of NaCl or the biodegradable choline chloride/urea eutectic mixture. Both C(sp3)-C(sp2) and C(sp2)-C(sp2) couplings have been found to proceed smoothly, with high chemoselectivity, under mild conditions (room temperature or 60 °C) in air, and in competition with protonolysis. Additional benefits include very short reaction times (20 s), good to excellent yields (up to 98 %), wide substrate scope, and the tolerance of a variety of functional groups. The proposed novel protocol is scalable, and the practicability of the method is further highlighted by an easy recycling of both the catalyst and the eutectic mixture or water.
Synthesis of Substituted Benzaldehydes via a Two-Step, One-Pot Reduction/Cross-Coupling Procedure
Heijnen, Dorus,Helbert, Hugo,Luurtsema, Gert,Elsinga, Philip H.,Feringa, Ben L.
supporting information, p. 4087 - 4091 (2019/06/14)
The synthesis of functionalized (benz)aldehydes, via a two-step, one-pot procedure, is presented. The method employs a stable aluminum hemiaminal as a tetrahedral intermediate, protecting a latent aldehyde, making it suitable for subsequent cross-coupling with (strong nucleophilic) organometallic reagents, leading to a variety of alkyl and aryl substituted benzaldehydes. This very fast methodology also facilitates the effective synthesis of a 11C radiolabeled aldehyde. Aluminum-ate complexes enable transmetalation of alkyl fragments onto palladium and subsequent cross-coupling.
Benzyllithiums bearing aldehyde carbonyl groups. A flash chemistry approach
Nagaki, Aiichiro,Tsuchihashi, Yuta,Haraki, Suguru,Yoshida, Jun-ichi
supporting information, p. 7140 - 7145 (2015/07/01)
Reductive lithiation of benzyl halides bearing aldehyde carbonyl groups followed by reaction with subsequently added electrophiles was successfully accomplished without affecting the carbonyl groups by taking advantage of short residence times in flow microreactors.
Room temperature observation of p-xylylenes by 1H NMR and evidence for diradical intermediates in their oligomerization
Trahanovsky, Walter S.,Lorimor, Steven P.
, p. 1784 - 1794 (2007/10/03)
p-Quinodimethanes (p-QDMs) are reactive molecules that have been invoked as transient intermediates in a number of reactions. Dilute solutions of benzene-based p-QDMs, p-xylylene (1), α-methyl-p-xylylene (10), and 2,5-dimethyl-p-xylylene (11) can be prepared by fluoride-induced elimination of trimethylsilyl acetate from the appropriate precursor. It has been found that these solutions are stable enough to allow these reactive p-QDMs to be observed by 1H NMR spectroscopy at room temperature. For the first time, the 13C NMR spectrum of p-QDM 1 was observed. After several hours at room temperature, these p-QDMs form dimers, trimers, and insoluble oligomers. Formation of trimers provides evidence that p-QDMs 1, 10, and 11 dimerize by a stepwise mechanism involving dimeric diradicals as intermediates.
NOVEL PROTECTING REAGENTS, PROTECTING GROUPS AND METHODS OF FORMING AND USING THE SAME
-
Page/Page column 30; 47, (2010/02/14)
New protecting reagents are provided that allow for the selective placement of a new protecting group onto a reactive site of a multifunctional compound. The reagents are 2, 3, and 4-trialkylsilylxylyl, triarylsilylxylyl or a combination of alkyl-aryl silylxylyl reagents (TIX reagents), which carry a TIX protecting group for protecting alcohols as ethers, urethanes, carbonates, acetals; amines as carbamates or ureas; and thiols as ethers or esters. The invention also provides methods of forming the 2, 3, and 4-TIX reagents; introducing the TIX protecting groups to molecules bearing hydroxyl groups, amine groups, or thiol groups; methods of removing the TIX protecting groups; and intermediate compounds formed during any one of these methods. The invention further provides methods useful in producing epothilones and analogs and derivatives thereof.
The trimethylsilyl xylyl (TIX) ether: A useful protecting group for alcohols
Reddy, Ch. Raji,Chittiboyina, Amar G.,Kache, Rajashaker,Jung, Jae-Chul,Watkins, E. Blake,Avery, Mitchell A.
, p. 1289 - 1295 (2007/10/03)
A new protecting group for alcohols, the p-trimethylsilyl xylyl (TIX) group has been developed. The TIX group is used to protect various alcohols under acidic as well as basic conditions. The protected ethers thus formed had noteworthy chemoselectivity upon deprotection in the presence of other benzyl ethers and commonly used protecting groups. The stability of the TIX group towards various reagents has also been examined.
Synthesis and photochemical properties of stilbenophanes tethered by silyl chains. Control of (2π + 2π) photocycloaddition, cis-trans photoisomerization, and photocyclization
Maeda, Hajime,Nishimura, Ko-Ichi,Mizuno, Kazuhiko,Yamaji, Minoru,Oshima, Juro,Tobita, Seiji
, p. 9693 - 9701 (2007/10/03)
Novel macrocyclic and medium-size stilbenophanes tethered by silyl chains were synthesized, and their photochemical and photophysical properties were examined. Direct photoirradiation of macrocyclic stilbenophanes gave intramolecular photocycloadducts ste
Methylenecyclopropane Rearrangement as a Probe for Free Radical Substituent Effects. ?. Values for Commonly Encountered Conjugating and Organometallic Groups
Creary, Xavier,Mehrsheikh-Mohammadi, M. E.,McDonald, Steven
, p. 3254 - 3263 (2007/10/02)
A series of 3-aryl-2,2-dimethylmethylenecyclopropanes, 8, with NO2, NMe2, vinyl, isopropenyl, phenyl, cyclopropyl, CH2SiMe3, SiMe3, SnMe3, , and HgCl substitution in the para position of the aromatic ring have been prepared.All rearrange thermally to the corresponding isopropylidenecyclopropanes 9 at rates that are substituent dependent.These commonly encountered substituents all enhance rearrangement rates relative to the unsubstituted analogue with p-NMe2 being the most effective.The rate enhancements are interpreted in terms of stabilization of the biradical intermediate by the para substituent.Rate data have allowed the assignment of ?. values for these groups, which have not been previously determined.The nitro group in the para position is also quite effective in increasing the rearrangement rate, which contrasts with the effect of this group on many other free radical reactions.Vinyl is somewhat more effective as a radical stabilizing group than is isopropenyl or phenyl, possibly due to steric interactions in the planar conformations necessary for conjugative stabilization by isopropenyl or phenyl.Trimethylsilyl,trimethylstannyl, and HgCl all enhance the methylenecyclopropane rearrangement rate, but only to a moderate extent.Boron containing substituents, where boron can act as an acceptor group, are among the more effective radical stabilizing groups, as implied by their effect on the rearrangement rate of 8.The cyclopropyl and CH2SiMe3 groups, which also enhance the rearrangement rate of 8 to a moderate extent, become even more effective radical stabilizing groups when present in conjunction with the carbethoxy group.These two conjugating groups are therefore capable of acting as donor groups in captodative radical stabilization.
