Dyotropic Rearrangement

2016 ◽  
Author(s):  
Vladimir I. Minkin
Keyword(s):  
Dyotropic Rearrangement

Unimolecular Isomerization of CH2FCD2Cl via the Interchange of Cl and F Atoms: Assignment of the Threshold Energy to the 1,2-Dyotropic Rearrangement

2013 ◽  
Vol 117 (31) ◽  
pp. 6717-6723 ◽  
Author(s):  
Mary K. Tucker ◽  
Samuel M. Rossabi ◽  
Corey E. McClintock ◽  
George L. Heard ◽  
D. W. Setser ◽  
...  
Keyword(s):  
Threshold Energy ◽  
Dyotropic Rearrangement

scholarly journals Reversible Shifting of a Chemical Equilibrium by Light: The Case of Keto-Enol Tautomerism of a β-Ketoester

2019 ◽  
Author(s):  
Andrey Lvov ◽  
Anton Yadykov ◽  
Konstantin Lyssenko ◽  
Valerii Shirinian ◽  
Marat M. Khusniyarov
Keyword(s):  
Blind Spot ◽  
Tautomeric Equilibrium ◽  
Equilibrium System ◽  
Enolic Form ◽  
Material Chemistry ◽  
Spectral Separation ◽  
Unexplored Area ◽  
Dyotropic Rearrangement ◽  
Spatio Temporal ◽  
Enol Tautomer

Manipulating the equilibrium between a ketone and an enol by exposure to light opens up ample opportunities in material chemistry and photopharmacology since it allows one to reversibly control the content of the enol tautomer, which acts as a hydrogen atom donor, with high spatio-temporal and energy resolution. Although tautomerization of β-ketoesters or their analogs was studied in numerous papers, their light-induced reversible tautomerization to give thermally stable enols (photoenolization) is an unexplored area. To shed light on this “blind spot”, we report an unprecedented property of diarylethene <b>2A</b> assembled from fragments of photoactive dithienylethene and a β-ketoester as part of the cyclohexenone bridge. In a pristine state, the tautomeric equilibrium of <b>2</b> is almost completely shifted towards the ketone. Photocyclization of the hexatriene system results in a new equilibrium system containing a significant fraction of the enol tautomer, both in polar and non-polar solvents. Due to the considerable spectral separation (35 nm), the keto-enol tautomerization process could be observed visually. The tendency of <b>2A </b>to undergo light-induced enolization was proved by isolating a related byproduct of photochemical 1,2-dyotropic rearrangement stabilized in the enolic form. Our results provide a novel tool for controlling the keto-enol tautomerism that might find use in the development of novel photocontrollable processes.

C–O Ring Formation

2015 ◽  
Author(s):  
Tristan H. Lambert
Keyword(s):  
Kinetic Resolution ◽  
Lewis Base ◽  
State University ◽  
Wayne State University ◽  
Northwestern University ◽  
Iminium Ion ◽  
Peking University ◽  
Complete Reversal ◽  
Dyotropic Rearrangement ◽  
The University

A reductive radical cyclization of tetrahydropyran 1 to form bicycle 2 using iron(II) chloride in the presence of NaBH4 was reported (Angew. Chem. Int. Ed. 2012, 51, 6942) by Louis Fensterbank and Cyril Ollivier at the University of Paris and Anny Jutand at the Ecole Normale Supérieure. The enantioselective conversion of tetrahydrofuran 3 to spirocycle 5 via iminium ion-catalyzed hydride transfer/cyclization was developed (Angew. Chem. Int. Ed. 2012, 51, 8811) by Yong-Qiang Tu at Lanzhou University. Daniel Romo at Texas A&M University showed (J. Am. Chem. Soc. 2012, 134, 13348) that enantioenriched tricyclic β-lactone 8 could be readily prepared via dyotropic rearrangement of the diketoacid 6 under catalysis by chiral Lewis base 7. A dyotropic rearrangement was also utilized (Angew. Chem. Int. Ed. 2012, 51, 6984) by Zhen Yang at Peking University, Tuoping Luo at H3 Biomedicine in Cambridge, MA, and Yefeng Tang at Tsinghua University for the conversion of 9 to the bicyclic lactone 10. In terms of the enantioselective synthesis of β-lactones, Karl Scheidt at Northwestern University found that NHC catalyst 12 effects (Angew. Chem. Int. Ed. 2012, 51, 7309) the dynamic kinetic resolution of aldehyde 11 to furnish the lactone 13 with very high ee. Meanwhile, Xiaomeng Feng at Sichuan University has developed (J. Am Chem. Soc. 2012, 134, 17023) a rare example of an enantioselective Baeyer-Villiger oxidation of 4-alkyl cyclohexanones such as 14. The diastereoselective preparation of tetrahydropyran 18 by Lewis acid-promoted cyclization of cyclopropane 17 was accomplished (Org. Lett. 2012, 14, 6258) by Jin Kun Cha at Wayne State University. Stephen J. Connon at the University of Dublin reported (Chem. Commun. 2012, 48, 6502) the formal cycloaddition of aryl succinic anhydrides such as 18 with aldehydes to produce γ-butyrolactones, including 20, in high ee. The stereodivergent cyclization of 21 via desilylation-induced heteroconjugate addition to produce the complex tetrahydropyran 22 was discovered (Org. Lett. 2012, 14, 5550) by Paul A. Clarke at the University of York. Remarkably, while TFA produced a 13:1 diastereomeric ratio in favor of the cis diastereomer 22, the use of TBAF resulted in complete reversal of diastereoselectivity.

Enantioselective and Collective Syntheses of Xanthanolides Involving a Controllable Dyotropic Rearrangement of cis-β-Lactones

2012 ◽  
Vol 51 (28) ◽  
pp. 6984-6988 ◽  
Author(s):  
Weiwu Ren ◽  
Yichao Bian ◽  
Ziyang Zhang ◽  
Hai Shang ◽  
Pengtao Zhang ◽  
...  
Keyword(s):  
Dyotropic Rearrangement

Hydroalumination of a Chlorotrialkynylsilane: Spontaneous Stepwise 1,3-Dyotropic Rearrangement via an Intermediate Silyl Cation

2014 ◽  
Vol 20 (28) ◽  
pp. 8771-8781 ◽  
Author(s):  
Werner Uhl ◽  
Jörg Bohnemann ◽  
Marcus Layh ◽  
Ernst-Ulrich Würthwein
Keyword(s):  
Dyotropic Rearrangement

Dissecting a Dyotropic Rearrangement

2010 ◽  
Vol 75 (5) ◽  
pp. 1693-1700 ◽  
Author(s):  
Rebecca L. Davis ◽  
Dean J. Tantillo
Keyword(s):  
Dyotropic Rearrangement

A new synthesis of substituted spiro butyrolactones via dyotropic rearrangement

1987 ◽  
Vol 28 (41) ◽  
pp. 4787-4788 ◽  
Author(s):  
T.Howard Black ◽  
William J. DuBay
Keyword(s):  
New Synthesis ◽  
Dyotropic Rearrangement
Sign in / Sign up

Export Citation Format

Share Document