79265-44-4Relevant academic research and scientific papers
Arylation and vinylation of α-diazocarbonyl compounds with boroxines
Peng, Cheng,Zhang, Wei,Yan, Guobing,Wang, Jianbo
supporting information; experimental part, p. 1667 - 1670 (2009/08/07)
An alternative approach for α-arylation and α-vinylation of carbonyl compounds is described: reaction between aryl-or vinylboroxines with α-diazocarbonyl compounds leads to the formation of α-arylated or α-vinylated carbonyl compounds under mild conditions.
Control of regioselectivity by the lone substituent through steric and electronic effects in the nitrosoarene ene reaction of deuterium-labeled trisubstituted alkenes
Adam, Waldemar,Krebs, Oliver,Orfanopoulos, Michael,Stratakis, Manolis
, p. 8395 - 8399 (2007/10/03)
For the ene reaction of 4-nitronitrosobenzene (ARNO) with a variety of primary and secondary lone alkyl-substituted substrates, the twix/twin regioselectivity is constant at about 85:15. In contrast, for the lone tert-butyl group and for lone aryl substituents, the twix regioisomer is obtained exclusively. These regioselectivities have been rationalized in terms of steric interactions and coordination between the enophile and the substrates in the transition states of the first reaction step.
Site specificity in the photooxidation of some trisubstituted alkenes in thionin-supported zeolite Na-Y. On the role of the alkali metal cation
Stratakis, Manolis,Froudakis, George
, p. 1369 - 1372 (2007/10/03)
(Matrix Presented) The less substituted side of some geminal dimethyl trisubstituted alkenes becomes significantly more reactive if photooxygenation takes place in thionin-supported zeolite Na-Y. These results are mainly attributed to a synergistic intera
Stereoselectivity control in reactions of tertiary 2-oxacycloalkyl radicals
Gerster,Renaud
, p. 1261 - 1267 (2007/10/03)
The stereochemical outcome of reactions mediated by tertiary 1,3-dioxolan-4-yl and oxiranyl cyclic radicals has been investigated. The presence of a very bulky substituent next to the radical center has a remarkable syn directing effect. These stereoselectivities are rationalized by a model which takes into account radical pyramidalization, steric interactions between the substituents attached to the cycle and steric interactions with the incoming radical trap.
Lithium 3-Lithio-3-tosylalkanoates: β-Acylvinyl Anion Equivalents of β-Lithiated α,β-Unsaturated Carboxylic Acids
Bonete, Pedro,Najera, Carmen
, p. 3202 - 3209 (2007/10/02)
The dilithiation of β-tosylated propanoic, 2-methylpropanoic, and butanoic acid 10 with n-butyllithium at -78 deg C leads to the corresponding lithium 3-lithio-3-tosylalkanoates 11.They react with different electrophilic reagents (deuterium oxide, iodine, trimethylchlorosilane, alkyl halides, and acyl chlorides) to give the corresponding 3-substituted tosylated alkanoic acids 12.When carbonyl compounds are allowed to react with intermediates 11 followed by in situ lactonization with trifluoroacetic anhydride and base-promoted elimination α,β-butenolides are obtained.This methodology is applied to the direct synthesis of the rosefuran lactone precursor 14cg, the O-benzyl derivative of (+/-)-umbelactone (14ch), and (+/-)-andirolactone (14ci).The alkylation and acylation reactions of organolithium compounds 11 followed by esterification with hydrogen chloride in methanol and treatment with 1,8-diazabicycloundec-7-ene (DBU) afford α,β- and/or β,γ-unsaturated esters 17 and/or 18 and unsaturated 4-keto esters 19, respectively.The last methodology has been applied to the synthesis of the unsaturated 4-keto ester 19ae precursor of the seco acid of (+/-)-pyrenophorin (22).
HIGHLY SELECTIVE SYNTHESIS OF ALLYLATED ARENES AND DIARYLMETHANES VIA PALLADIUM-CATALYZED CROSS COUPLING INVOLVING BENZYLIC DERIVATIVES
Negishi, Ei-ichi,Matsushita, Hajime,Okukado, Nobuhisa
, p. 2715 - 2718 (2007/10/02)
The Pd-catalyzed cross coupling of either benzylzincs with alkenyl halides or alkenylalanes with benzyl halides provides highly selective and expeditious routes to allylated arenes.
