7167-30-8Relevant academic research and scientific papers
Enantioselective Diels-Alder Reactions of Carboxylic Ester Dienophiles Catalysed by Titanium-Based Chiral Lewis Acid
Choughule, Yogesh K.,Patwardhan, Anand V.
, p. 921 - 926 (2016/07/06)
A new titanium-based chiral Lewis acid 1 has been developed using (1R,2R)-1,2-bis-(2-methoxyphenyl)-ethane-1,2-diol as a chiral vicinal diol ligand. This chiral catalyst was found to exhibit uniformly high enantioselectivity towards carboxylic ester dienophiles in Diels-Alder reactions. The chiral vicinal ligand (1R,2R)-1,2-bis-(2-methoxyphenyl)-ethane-1,2-diol is inexpensive and is easily accessible.
Hydrophobic effects are dominant over secondary orbital interactions for a simple Diets-Alder reaction in salt solutions
Sarma, Diganta,Kumar, Anil
, p. 2199 - 2202 (2007/10/03)
The stereoselectivity ratios for a Diels-Alder reaction between cyclopentadiene with methyl trans-crotonate carried out in salt solutions demonstrate the dominance of hydrophobic effects over secondary orbital interactions.
Hydrophobic effects in a simple Diels-Alder reaction in water
Sarma, Diganta,Pawar, Sanjay S.,Deshpande, Suvarna S.,Kumar, Anil
, p. 3957 - 3958 (2007/10/03)
The endo/exo ratio for a simple Diels-Alder reaction carried out in water has been used to argue that hydrophobic effects can dominate the geometries of the transition states.
Converting exo-Selective Diels-Alder Reaction to endo-Selective in Chloroloaluminate Ionic Liquids
Kumar, Anil,Pawar, Sanjay S.
, p. 1419 - 1420 (2007/10/03)
The endo:exo ratio of 0.35:1 for the reaction of cyclopentadiene with methyl methacrylate observed in organic solvents can be converted to 3:1 in chloroaluminate ionic liquids with their effective reuse in Diels-Alder reactions.
Trimethylsilyl bis(trifluoromethanesulfonyl)imide as a tolerant and environmentally benign Lewis acid catalyst of the Diels-Alder reaction
Mathieu, Benoit,Ghosez, Léon
, p. 8219 - 8226 (2007/10/03)
N-trimethylsilyl bis(trifluoromethanesulfonyl)imide (TMSNTf2) was readily prepared in situ by protodesilylation of trimethylsilane, allyl- or phenyltrimethylsilane with bis(trifluoromethylsulfonyl)imide. NMR studies showed that TMSNTf2 was much more effective than TMSOTf in complexing the carbonyl group of trans-methylcrotonate. As a result, TMSNTf2 was found to be superior to TMSOTf as a catalyst for the Diels-Alder reaction of α,β-unsaturated esters with a wide variety of dienes. In contrast to many metal derived Lewis acids, TMSNTf2 was found tolerant of many sensitive functional groups present in the diene partner.
DMAP-promoted racemization-free deacylation of carboxthioimide adducts: Carboxthioimide as a versatile carboxy protecting group
Su, Dah-Wei,Wang, Ying-Chuan,Yan, Tu-Hsin
, p. 545 - 546 (2007/10/03)
The DMAP-promoted deacylation of carboxthioimide adducts can be directed to form either acid or various ester protecting groups with no detectable levels of epimerization.
REACTIVITY AND STEREOSELECTIVITY IN THE DIELS-ALDER REACTIONS BETWEEN CYCLOPENTADIENE AND SOME α,β-UNSATURATED THIOESTERS.
Wladislaw, Blanka,Marzorati, Liliana,Gruber, Jonas
, p. 185 - 188 (2007/10/02)
Some new norbornene thioester derivatives of endo configuration are synthesized.Proofs are provided that thioester group has more preference for endo configuration than the ester group.
Asymmetric Diels-Alder Reaction Using (S)-Pyroglutamic Acid Derivatives as Chiral Dienophiles
Ikota, Nobuo
, p. 2219 - 2221 (2007/10/02)
Asymmetric Diels-Alder reaction of cyclopentadiene with chiral dienophiles (3) derived from (S)-pyroglutamic acid derivatives was performed in the presence of a Lewis acid such as diethylaluminium chloride in toluene to afford the cycloadducts with high diastereoselectivity.Keywords asymmetric reaction; Diels-Alder reaction; (S)-pyroglutamic acid; chiral dienophile; diethylaluminium chloride; (2+4)cycloaddition
IRIDOIDS : STEREOSPECIFIC SYNTHESIS OF FUNCTIONALIZED CYCLOPENTANOID INTERMEDIATES VIA BICYCLOHEPTANONES
Callant, P.,Storme, P.,Van der Eycken, E.,Vandewalle, M.
, p. 5797 - 5800 (2007/10/02)
An efficient synthesis of functionalized trialkyl substituted cyclopentanoids is presented.Stereocontrol is secured by their formation from norbornane precursors.The strategy is illustrated by the total synthesis of (+/-)-boschnialactone (13), (+/-)-teucriumlactone C (14), and (+/-)-loganin (2).
Cycloadditions of Allyl Cations, 28. Novel Diels-Alder Additions via Acid Catalyzed Reactions of 4-Methyl-3-penten-2-ol with Cyclopentadiene and Cyclohexadiene in Two Phases. Formation of Monocyclic, Bicyclic, and Tricyclic Adducts and Double Fragmentation of a Norbornenylcarbinol
Hoffmann, H. M. R.,Vathke-Ernst, Heidrun
, p. 2208 - 2216 (2007/10/02)
4-Methyl-3-penten-2-ol (1) and cyclopentadiene react in an acidic two phase system at 0 deg C to form allylcyclopentenols 2 and norbornenylcarbinols 4.At 50 deg C and under similar conditions, 2 as well as 4 are equilibrated to allylcyclopentadienes 3, bicyclic olefins 5 and 6, and tricyclic ether 7.With a comparatively reactive dehydrating agent (SOCl2/pyridine), norbornenylcarbinol 4 suffers double fragmentation to give dimeric dienes C12H20, which were also obtained independently by acid catalyzed dehydrative dimerization of allyl alcohol 1. - The endo/exo selectivity for the formation of epimeric norbornenylcarbinols 4 from cyclopentadiene and 1 is similar to that of the AlCl3-catalyzed cycloaddition of methyl 2-butenoate and cyclopentadiene (13:1).The acid catalyzed two phase reaction of cyclohexadiene and 1 at room temperature gives the substituted bicyclooctene endo-13 in 19 - 23 percent yield.
