- Taking advantage of lithium monohalocarbenoid intrinsic α-elimination in 2-MeTHF: controlled epoxide ring-openingen routeto halohydrins
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The intrinsic degradative α-elimination of Li carbenoids somehow complicates their use in synthesis as C1-synthons. Nevertheless, we herein report how boosting such an α-elimination is a straightforward strategy for accomplishing controlled ring-opening of epoxides to furnish the corresponding β-halohydrins. Crucial for the development of the method is the use of the eco-friendly solvent 2-MeTHF, which forces the degradation of the incipient monohalolithium, due to the very limited stabilizing effect of this solvent on the chemical integrity of the carbenoid. With this approach, high yields of the targeted compounds are consistently obtained under very high regiocontrol and, despite the basic nature of the reagents, no racemization of enantiopure materials is observed.
- Ielo, Laura,Miele, Margherita,Pillari, Veronica,Senatore, Raffaele,Mirabile, Salvatore,Gitto, Rosaria,Holzer, Wolfgang,Alcántara, Andrés R.,Pace, Vittorio
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supporting information
p. 2038 - 2043
(2021/03/16)
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- A practical and enantiospecific synthesis of (-)-(R)- and (+)-(S)-piperidin-3-ols
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A highly enantiospecific, azide-free synthesis of (-)-(R)- and (+)-(S)-piperidin-3-ol in excellent yield was developed. The key step of the synthesis involves the enantiospecific ring openings of enantiomerically pure (R)- and (S)-2-(oxiran-2-ylmethyl)-1H-isoindole-1,3(2H)-diones with the diethyl malonate anion and subsequent decarboxylation.
- Babu, Meruva Suresh,Raghunadh, Akula,Ramulu, Konda,Dahanukar, Vilas H.,Syam Kumar, Unniaran K.,Dubey, P. Kumar
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p. 1507 - 1515
(2015/02/19)
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- 2-Methyltetrahydrofuran as a suitable green solvent for phthalimide functionalization promoted by supported KF
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An efficient chemoselective nitrogen functionalization of phthalimides by using KF-Alumina in 2-methyltetrahydrofuran, a solvent obtained from renewal sources, is described.
- Pace, Vittorio,Hoyos, Pilar,Fernandez, Maria,Sinisterra, Jose V.,Alcantara, Andres R.
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supporting information; experimental part
p. 1380 - 1382
(2010/09/05)
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- PROCESS FOR THE PREPARATION OF CHIRAL GLYCIDYLPHTHALIMIDE IN HIGHLY OPTICAL PURITY
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The present invention relates to a process for the preparation of highly optical pure glycidylphthalimide. More particularly, the present invention relates to a process for the preparation of chiral glycidylphthalimide, which comprises the steps of reacting an optically active 3-susbstituted 1-amino-2-propanol acid addition salt with phthalic anhydride in a presence of a base to obtain N-(3-substituted-2-hydroxypropyl)phthalimide and subjecting the obtained compound to an epoxide cyclization reaction to prepare the targeted glycidylphthalimide. According to the process, the chirality of the starting material is substantially retained throughout overall procedures. Therefore, the process can prepare the targeted glycidylphthalimide in an optically pure form having 99%ee or higher. And, the reactions are carried out under mild conditions through overall procedures and in a single reaction vessel without any special purification. This increases the yield of the target compound.
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Page/Page column 9-10
(2008/06/13)
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