CF₃SO₂X (X = Na, Cl) as reagents for trifluoromethylation, trifluoromethylsulfenyl-, -sulfinyl- and -sulfonylation and chlorination. Part 2: Use of CF₃SO₂Cl

• Hélène Chachignon,
• Hélène Guyon and
• Dominique Cahard

Beilstein J. Org. Chem. 2017, 13, 2800–2818, doi:10.3762/bjoc.13.273

• radical cyclisation, to yield the tetralin derivative 12 (Scheme 12) [17]. In 2017, Liu and co-workers focused on N-alkenylurea derivatives 13, and from which they developed an asymmetric radical aminotrifluoromethylation methodology, based on a copper salt/chiral phosphoric acid dual-catalytic system [18

• single-electron transfer (SET) between CF3SO2Cl and the association CuBr/chiral phosphoric acid. In the process, SO2 and HCl were released, but the latter was scavenged by Ag2CO3, minimising its impact on the reaction process by notably avoiding hydroamination side reactions. The trifluoromethyl radical

• , replacing the chiral phosphoric acid with diphenyl phosphate (Scheme 14) [20]. Liu’s research group was interested as well in 1,2-difunctionalisation of unactivated alkenes. In this context, they developed two distinct approaches allowing to perform radical-mediated 1,2-formyl- [21] or 1,2

Phosphazene-catalyzed desymmetrization of cyclohexadienones by dithiane addition

• Matthew A. Horwitz,
• Elisabetta Massolo and
• Jeffrey S. Johnson

Beilstein J. Org. Chem. 2017, 13, 762–767, doi:10.3762/bjoc.13.75

• enantioselectively delivered oxabicyclo[4.3.0]nonanes [17]; the Lautens and Lan groups have also contributed to the further development of this reaction [18][19]. The Rovis group employed cyclohexadienone hydroperoxides in a chiral phosphoric acid-catalyzed [1,2]/[1,4]-addition cascade [20]. The same group also

Stereo- and regioselectivity of the hetero-Diels–Alder reaction of nitroso derivatives with conjugated dienes

• Lucie Brulíková,
• Aidan Harrison,
• Marvin J. Miller and
• Jan Hlaváč

Beilstein J. Org. Chem. 2016, 12, 1949–1980, doi:10.3762/bjoc.12.184

• another method for the asymmetric nitroso hetero-Diels–Alder reaction, using the Wightman chloronitroso reagent 58 as a chiral dienophile (Scheme 31). In 2015, Masson published a chiral phosphoric acid-catalyzed asymmetric nitroso hetero-Diels–Alder reaction of nitrosoarenes with substituted

Rearrangements of organic peroxides and related processes

• Ivan A. Yaremenko,
• Vera A. Vil’,
• Dmitry V. Demchuk and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2016, 12, 1647–1748, doi:10.3762/bjoc.12.162

• [280][281][282] as the catalyst. The obtained asymmetric oxidation products can be used in the multistep synthesis of new biologically active compounds. Possible mechanisms for the asymmetric oxidation of 3-substituted cyclobutanone 96a with H2O2 catalyzed by chiral phosphoric acid are presented in

Catalytic asymmetric synthesis of biologically important 3-hydroxyoxindoles: an update

• Bin Yu,
• Hui Xing,
• De-Quan Yu and
• Hong-Min Liu

Beilstein J. Org. Chem. 2016, 12, 1000–1039, doi:10.3762/bjoc.12.98

• cyclization, giving the tricyclic N-heterocyclic core. Very recently, Shi and co-workers reported the chiral phosphoric acid (CPA, cat. 31)-catalyzed asymmetric dearomatization reactions of tryptamines with 3-indolyl-3-hydroxyoxindoles, affording the indole-containing tricyclic N-heterocycles in a highly

Silver and gold-catalyzed multicomponent reactions

• Giorgio Abbiati and
• Elisabetta Rossi

Beilstein J. Org. Chem. 2014, 10, 481–513, doi:10.3762/bjoc.10.46

Efficient synthesis of dihydropyrimidinones via a three-component Biginelli-type reaction of urea, alkylaldehyde and arylaldehyde

• Haijun Qu,
• Xuejian Li,
• Fan Mo and
• Xufeng Lin

Beilstein J. Org. Chem. 2013, 9, 2846–2851, doi:10.3762/bjoc.9.320

• chiral spirocyclic SPINOL-phosphoric acids. Keywords: Biginelli-type reaction; chiral phosphoric acid; dihydropyrimidinone; iodine; multicomponent reaction; Introduction The dihydropyrimidinones (DHPMs) have exhibited interesting and multifaceted biological activities, such as antiviral, antitumor

Organocatalyzed enantioselective desymmetrization of aziridines and epoxides

• Ping-An Wang

Beilstein J. Org. Chem. 2013, 9, 1677–1695, doi:10.3762/bjoc.9.192

• mol % of commercially available chiral phosphoric acid OC-21 as a catalyst, Lattanzi [46] and colleagues have developed a facile desymmetrization of meso-N-acylaziridines with Me3SiSPh to produce β-(N-acylamino)phenyl thioethers (Scheme 5, 37 to 44) in high enantioselectivities (78–99% ee

• hindered air-stable selenosilane t-BuMe2SiSePh was used as a sole nucleophile for desymmetrization of meso-N-acylaziridines in the presence of 10 mol % of chiral phosphoric acid OC-21, the good conversions and enantioselectivities were accomplished in toluene but with a very long reaction time (usually up

• reagents (Me3SiN3, Me3SiSMe, Me3SiSPh, Me3SiSBn, Me3SiNCS and Me3SiSePh/PhSeH) by chiral phosphoric acid OC-21. It was found that both purchased and synthetic OC-21 exhibited high catalytic activities and enantioselective inductions in the desymmetrization of meso-aziridines. Samples of OC-21 were washed

Organocatalytic asymmetric selenofunctionalization of tryptamine for the synthesis of hexahydropyrrolo[2,3-b]indole derivatives

• Qiang Wei,
• Ya-Yi Wang,
• Yu-Liu Du and
• Liu-Zhu Gong

Beilstein J. Org. Chem. 2013, 9, 1559–1564, doi:10.3762/bjoc.9.177

• Qiang Wei Ya-Yi Wang Yu-Liu Du Liu-Zhu Gong Hefei National Laboratory for Physical Sciences at the Microscale and Department of Chemistry, University of Science and Technology of China, Hefei, 230026, China 10.3762/bjoc.9.177 Abstract A chiral phosphoric acid-catalyzed selenofunctionalization of

• tryptamine derivatives provides access to 3a-(phenylselenyl)-1,2,3,3a,8,8a-hexahydropyrrolo[2,3-b]indole derivatives in high yields and with synthetically useful levels of enantioselectivity (up to 89% ee). Keywords: catalysis; chiral phosphoric acid; hexahydropyrrolo[2,3-b]indole; indole alkaloids; natural

• reaction conditions, a variety of tryptamine analogues were synthesized for this chiral phosphoric acid-catalyzed asymmetric selenofunctionalization. As shown in Figure 2, no matter what the chemical and electronic feature of the substituents on the benzene moiety of either substrates or N-PSP, various

Organocatalytic C–H activation reactions

• Subhas Chandra Pan

Beilstein J. Org. Chem. 2012, 8, 1374–1384, doi:10.3762/bjoc.8.159

• regenerated (Scheme 11). The following year, Akiyama and co-workers reported another organocatalytic asymmetric synthesis of tetrahydroquinolines using chiral phosphoric acid as the catalyst [25]. In this instance, benzylidene malonates were used as the hydride acceptor. Another important feature of this

• report by the Akiyama group is the predominant use of N,N-dibenzylamine as the amine donor in their reaction instead of cyclic tertiary amines as used by the Kim group. The present authors employed biphenyl-based chiral phosphoric acid catalysts 15a and 15b and moderate to high yields (45–95%) and

• chirality in cationic intermediate C (Scheme 13). Nucleophilic attack then occurred from the same side of the transferred hydrogen to provide (S)-19. The authors concluded that selective activation of one of the enantiotopic hydrogen atoms by chiral phosphoric acid is the main reason for obtaining

Recent advances in the gold-catalyzed additions to C–C multiple bonds

• He Huang,
• Yu Zhou and
• Hong Liu

Beilstein J. Org. Chem. 2011, 7, 897–936, doi:10.3762/bjoc.7.103

• a highly enantioselective three-component (393–395) cascade reaction which involved an enantioselective [4 + 2] cycloaddition reaction catalyzed by a chiral phosphoric acid and a subsequent catalytic intramolecular hydroamination by a gold(I) complex (Scheme 64) [180]. Further studies revealed that