Asymmetric desymmetrization of dialkyl bicyclo[2.2.1]hept-2,5-diene-2,3-dicarboxylates by a thermophilic esterase/lipase
摘要:
A thermophilic enzyme efficiently monohydrolyzed a series of meso diesters, dialkyl bicycle[2.2.1]hept-2,5-diene-2,3-dicarboxylates, in high chemical yields (72-98%) and high enantiomeric purities (>99% e.e.) in all the cases examined. (C) 2002 Elsevier Science Ltd. All rights reserved.
Practical selective monohydrolysis of bulky symmetric diesters: Comparing with sonochemistry
作者:Jianjun Shi、Tian Zhao、Satomi Niwayama
DOI:10.1016/j.tet.2018.09.051
日期:2018.11
The conditions of the practical selective monohydrolysis of symmetric diesters we previously reported have been modified and applied to selective monohydrolysis of bulky symmetric diesters. While ultrasound is generally considered effective for two-phase reactions, its effect actually turned out to be rather marginal. Instead, use of a larger proportion of a polar aprotic co-solvent, DMSO, and aqueous
The palladium-catalyzedcyclopropanation of strainedalkenes with 3-pinacolatoboryl-1-arylallyl carboxylates was explored. The reactions proceeded smoothly under mild conditions, and the cyclopropanation products were obtained in good to high yields with high diastereoselectivities if CsF, 18-crown-6, and molecular sieves were used as additives. The reaction was hypothesized to proceed through the
Ring expansion of substituted norbornadienes for the synthesis of mono- and disubstituted 2-azabicyclo[3.2.1]octadienes
作者:Nova Emelda、Stephen C. Bergmeier
DOI:10.1016/j.tetlet.2008.06.123
日期:2008.9
substituted 2-azabicyclo[3.2.1]octadiene system via reaction with toluenesulfonyl azide. We have found that both and mono- and disubstituted norbornadienes will undergo the cycloaddition/rearrangement sequence to provide the bicyclooctadiene ringsystem as a single regioisomer. The 2-azabicyclo[3.2.1]octane ringsystem can be prepared from the unsaturated 2-azabicyclo[3.2.1]octadiene ringsystem.
Asymmetric monohydrolysis of a series of norbornanederivatives by a thermophilic esterase/lipase library was examined. Three esterases/lipases showed high enantioselectivities toward dialkyl bicyclo[2.2.1]hepta-2,5-diene-2,3-dicarboxylates with high chemical yields.
Tandem Suzuki Coupling−Norbornadiene Insertion Reactions. A Convenient Route to 5,6-Diarylnorbornene Compounds
作者:Katie M. Shaulis、Bradley L. Hoskin、John R. Townsend、Felix E. Goodson、Christopher D. Incarvito、Arnold L. Rheingold
DOI:10.1021/jo016212b
日期:2002.8.1
This paper presents optimization studies on a palladium-catalyzed tandem norbornadiene insertion-Suzuki coupling reaction, which provides a one-pot procedure for the formation of diarylnorbornene derivatives. This procedure allows for the synthesis of these compounds from readily available aryl halides, arylboronic acids, and substituted norbornadienes.