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