51422-70-9Relevant academic research and scientific papers
Stereoselective [4+2]-Cycloaddition with Chiral Alkenylboranes
Brown, M. Kevin,Houk, K. N.,Ni, Dongshun,Witherspoon, Brittany P.,Zhang, Hong,Zhou, Chen
supporting information, p. 11432 - 11439 (2020/05/18)
A method for the stereoselective [4+2]-cycloaddition of alkenylboranes and dienes is presented. This transformation was accomplished through the introduction of a new strategy that involves the use of chiral N-protonated alkenyl oxazaborolidines as dieneophiles. The reaction leads to the formation of products that can be readily derivatized to more complex structural motifs through stereospecific transformations of the C?B bond such as oxidation and homologation. Detailed computation evaluation of the reaction has uncovered a surprising role of the counterion on stereoselectivity.
Alkylhalovinylboranes: a new class of Diels-Alder dienophiles
Pisano, Pablo L.,Pellegrinet, Silvina C.
, p. 33864 - 33871 (2018/10/20)
The Diels-Alder reactions of alkylhalovinylboranes have been investigated theoretically and experimentally. Alkylhalovinylboranes presented higher reactivity than the corresponding dialkylvinylboranes. Although endo/exo selectivities were high for the reactions with cyclopentadiene, facial selectivities for the chiral analogues were low. Our results demonstrate that the replacement of an alkyl group on the boron atom by a halogen increases the dienophilicity considerably.
Evaluation of the use of mandelate derivatives to determine the enantiomeric purity and the absolute configuration of secondary cyclohexenols
Sarotti, Ariel M.,Pisano, Pablo L.,Pellegrinet, Silvina C.
body text, p. 343 - 357 (2011/06/10)
The use of mandelate derivatives to determine the enantiomeric purity and the absolute configuration of isomeric mixtures of bicyclic and monocyclic secondary cyclohexenols was investigated. Synthesis, NMR and conformational analyses of the derivatives were performed and Gauge-Independent Atomic Orbital (GIAO) 1H NMR Boltzmann weighted average chemical shifts were computed. The studied methodology proved to be of practical value for most of the systems under study. ARKAT-USA, Inc.
A facile microwave-assisted Diels-Alder reaction of vinylboronates
Sarotti, Ariel M.,Pisano, Pablo L.,Pellegrinet, Silvina C.
supporting information; experimental part, p. 5069 - 5073 (2010/12/25)
The Diels-Alder reaction of vinylboronates can be easily performed using microwave irradiation giving excellent yields of the cycloadducts. Pinacol vinylboronate was the reagent of choice due to its stability towards hydrolysis, operational simplicity and yields of Diels-Alder products. To the best of our knowledge, this is the first example of microwave-assisted Diels-Alder reaction of boron-substituted dienophiles. Subsequent in situ oxidation of the cycloadducts with alkaline hydrogen peroxide afforded the alcohols efficiently.
Syntheses with organoboranes. IX. Vinyl- and 1-alkenyldichloroboranes as ethylene and 1-alkene equivalents for the Diels-Alder reaction
Zaidlewicz, Marek,Binkul, Jacek R.,Sokol, Wojciech
, p. 354 - 362 (2007/10/03)
Vinyl- and 1-alkenyldichloroboranes were used as dienophiles for the Diels-Alder reaction with representative aliphatic and cyclic 1,3-dienes. The organoborane adducts were transformed into the corresponding olefins either by protonolysis or by oxidation-mesylation-reduction. Direct protonolysis of the adducts gave in most cases mixtures of olefins whereas the reduction of mesylates with lithium triethylborohydride produced pure olefins in good yields.
Reaction of Azoalkanes with Isolable Cation Radical Salts
Engel, Paul S.,Robertson, Donald M.,Scholz, John N.,Shine, Henry J.
, p. 6178 - 6187 (2007/10/02)
Three tertiary azoalkanes related in the sense acyclic, cyclic, and bicyclic are shown to evolve nitrogen upon oxidation with stable cation radical salts.Thus azo-tert-octane (ATO), 3,3,6,6-tetramethyl-1,2-diazacyclohexene (TMDAC), and 1,4-dimethyl-2,3-diazabicyclooct-2-ene (Me2DBO) react rapidly with thianthrenium perchlorate (Th(.1+)ClO4(1-)), tris(p-bromophenyl)aminium hexachloroantimonate (TBPA(.1+)SbCl6(1-)), and TBPA(.1+)SbF6(1-).The ether and olefin products, which are formed in high yield in CH2Cl2/MeOH solvent, are not those expected from the usual free-radical decomposition of azoalkanes but instead implicate carbocations.Althrough the reaction stoichiometry clearly requires 2 equiv of cation radical salt to one of azoalkane, the mechanism is not yet clearly defined.A complication in these studies is found in the ability of certain cation radical salts to oxidize more azoalkane than expected based on the 2:1 stoichiometry.
SYNTHESIS OF Z-ALLYLIC ACETATES VIA FRAGMENTATION OF CYCLIC HOMOALLYLIC ALCOHOLS
Ramaiah, P.,Rao, A. S.
, p. 2119 - 2120 (2007/10/02)
Z-Allylic acetates (6a-6e) having an additional functional group as ketone or aldehyde were prepared via the fragmentation of the homoallylic alcohols (5a-5e) in the presence of lead tetraacetate.
Sila-Perfumes, 5. - Sila-Terpineol and Related Compounds
Wrobel, Dieter,Wannagat, Ulrich
, p. 211 - 219 (2007/10/02)
Dimethyl(4-methyl-3-cyclohexenyl)silanol (6), the sila derivative of α-terpineol - a component of many ethereal oils with the fragrance of lilac - could be synthesized according to Scheme 1.The intensity of the fragrance of 6 is comparable with the natura
CYCLOHEXENOL ANNULATION VIA THE ALKOXY-ACCELERATED REARRANGEMENT OF VINYLCYCLOBUTANES
Danheiser, Rick L.,Martinez-Davila, Carlos,Sard, Howard
, p. 3943 - 3950 (2007/10/02)
The lithium and potassium salts of 2-vinylcyclobutanols undergo vinylcyclobutane rearrangement at 25-70 gradC, providing an efficient method for the synthesis of 3-cyclohexenol derivatives. 2-Vinylcyclobutanones are prepared from α,β-unsaturated carbonyl
