There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

2. Essential Components: Earlier Developments 5449 2.1. Activated alkenes/alkynes 5450 2.1.1. Acyclic activated alkenes/ alkynes 5450 2.1.2. Cyclic activated alkenes 5451 2.2. Electrophiles 5451 2.3. Catalysts 5452 3. Essential Components: Recent Developments 5452 3.1. Activated Alkenes/Alkynes 5452 3.2. Electrophiles 5460 3.3. Catalysts 5477 4. Asymmetric Baylis-Hillman Reaction: Earlier Developments 5495

Recent contributions from the Baylis-Hillman reaction to organic chemistry.

Building on the successful experience in operating the DarkSide-50 detector, the DarkSide Collaboration is going to construct DarkSide-20k, a direct WIMP search detector using a two-phase Liquid Argon Time Projection Chamber (LAr TPC) with an active (fiducial) mass of 23 t (20 t). This paper describes a preliminary design for the experiment, in which the DarkSide-20k LAr TPC is deployed within a shield/veto with a spherical Liquid Scintillator Veto (LSV) inside a cylindrical Water Cherenkov Veto (WCV). This preliminary design provides a baseline for the experiment to achieve its physics goals, while further development work will lead to the final optimization of the detector parameters and an eventual technical design. Operation of DarkSide-50 demonstrated a major reduction in the dominant 39Ar background when using argon extracted from an underground source, before applying pulse shape analysis. Data from DarkSide-50, in combination with MC simulation and analytical modeling, shows that a rejection factor for discrimination between electron and nuclear recoils of $>3 \times 10^{9}$
 is achievable. This, along with the use of the veto system and utilizing silicon photomultipliers in the LAr TPC, are the keys to unlocking the path to large LAr TPC detector masses, while maintaining an experiment in which less than $< 0.1$
 events (other than $\nu$
 -induced nuclear recoils) is expected to occur within the WIMP search region during the planned exposure. DarkSide-20k will have ultra-low backgrounds than can be measured in situ, giving sensitivity to WIMP-nucleon cross sections of $1.2 \times 10^{-47}$
 cm2 (
 $1.1 \times 10^{-46}$
 cm2) for WIMPs of 1 TeV/c2 (10 TeV/c2) mass, to be achieved during a 5 yr run producing an exposure of 100 t yr free from any instrumental background.

DarkSide-20k: A 20 tonne two-phase LAr TPC for direct dark matter detection at LNGS

2.3.3. Fluorinated Imines 7 2.3.4. Arylimino Acetates 8 2.3.5. In Situ Generated Iminium Ions 8 2.4. -Substituted Michael Acceptors 8 2.5. Formation of Unexpected Products 10 2.5.1. Reaction with Cyclic Enones 11 2.5.2. Reaction with Vinyl Ketones 11 2.5.3. Reaction with Acrolein 12 2.5.4. Reaction with Activated Allenes and Alkynes 12 2.5.5. Reaction of Salicyl N-Tosylimines 12 3. Stereoselective Synthesis 13 3.1. Use of Chiral Aldehydes 13 3.2. Use of Chiral Bases 13 3.3. Use of Chiral Phosphines 16 3.4. Use of a Chiral Sulfide 18 3.5. Use of an Organocatalyst Derived from BINOL 18 3.6. Use of a Chiral Ligand Derived from Thiourea 18 3.7. Use of Chiral Ionic Liquids 18 4. Alternative Access Pathways to -Aminocarbonyl Compounds 18

aza-Baylis−Hillman Reaction

Advances in the Baylis–Hillman reaction-assisted synthesis of cyclic frameworks

Regioselective synthesis of 1-arylnaphthalenes from N-tosylaziridine derivatives

Synthesis of 3-aryl-3-hydroxypyrrolidin-2-ones and 2-benzyl-9b-hydroxy-3,3a,5,9b-tetrahydro-2H-pyrrolo[3,4-c]quinoline-1,4-dione derivatives from the Baylis–Hillman adducts of isatins

Regioselective construction of polysubstituted phenols from Baylis-Hillman adducts via formal [4+2] annulation strategy

Recently, we have reported a variety of chemical transformations of the Baylis-Hillman adducts into useful heterocyclic compounds. Very recently, we published the synthesis of 3-benzylquinolin-2-ols from the Baylis-Hillman adducts of ethyl acrylate bearing aniline moiety at the secondary position. 3-Benzylquinolin-2-ols could be formed via the sequential aza-Claisen rearrangement of the adduct in PPA, amide bond formation, and the following isomerization with the aid of DBU as shown in Scheme 1. In this paper we would like to report our results on the synthesis of polysubstituted quinolines from the BaylisHillman adducts of alkyl vinyl ketones. As exemplified in Scheme 2, the required starting materials 2 were synthesized from the acetates of the Baylis-Hillman adducts of methyl vinyl ketone and ethyl vinyl ketone via the corresponding DABCO salts according to the reported procedure. In the reaction, however, cinnamyl amine derivatives 3 were isolated in variable yields (6-37%) depending upon the nature of anilines (Table 1) as side products. The formation of primary adducts 3 from 2 under the reaction conditions can be explained by sequential addition and elimination of aniline, presumably due to the higher electrophilicity of the β-carbon (marked with asterisk) of 2 than the cases of ethyl acrylate (Scheme 1). As can be seen easily in the ratios of 2 and 3 (Table 1), the amounts of primary products 3 were gradually increased according to the increase of the nucleophilicity of anilines. With the compound 2a in hand we examined the reaction in PPA at various reaction temperatures. Mixed solvent system of PPA and 1,2-dichloroethane was used in order to

/pdf/synthesis-of-polysubstituted-quinolines-from-the-acetates-of-4vr53ct1w5.pdf

Seung Chan Kim

Papers

Regioselective synthesis of 1-arylnaphthalenes from N-tosylaziridine derivatives

Synthesis of 3-aryl-3-hydroxypyrrolidin-2-ones and 2-benzyl-9b-hydroxy-3,3a,5,9b-tetrahydro-2H-pyrrolo[3,4-c]quinoline-1,4-dione derivatives from the Baylis–Hillman adducts of isatins

Regioselective construction of polysubstituted phenols from Baylis-Hillman adducts via formal [4+2] annulation strategy

Synthesis of Polysubstituted Quinolines from the Acetates of Baylis-Hillman Adducts: Aza-Claisen Rearrangement as the Key Step

Synthesis of poly-substituted benzenes starting from Baylis–Hillman adducts: DBU-assisted unusual dehydrogenation