Biochemistry of fluoroprolines: the prospect of making fluorine a bioelement

• Vladimir Kubyshkin,
• Rebecca Davis and
• Nediljko Budisa

Beilstein J. Org. Chem. 2021, 17, 439–460, doi:10.3762/bjoc.17.40

Synthetic mRNA capping

• Fabian Muttach,
• Nils Muthmann and
• Andrea Rentmeister

Beilstein J. Org. Chem. 2017, 13, 2819–2832, doi:10.3762/bjoc.13.274

• modifications no translational activity was observed in vitro, the N7-benzyl modification showed residual activity. This may be attributed to a stacking of the benzyl-moiety between tryptophans in the eIF4E binding pocket [63][66][97]. Enzymatic modification at the N2- and N7-position can also be combined to

Conjugate addition–enantioselective protonation reactions

• James P. Phelan and
• Jonathan A. Ellman

Beilstein J. Org. Chem. 2016, 12, 1203–1228, doi:10.3762/bjoc.12.116

• for the synthesis of biologically active molecules, including natural products and drugs. The Reisman group has reported a Friedel–Crafts conjugate addition–enantioselective protonation for the synthesis of tryptophans 17 from 2-substituted indoles 14 and methyl 2-acetamidoacrylate (15) using

• –Crafts conjugate addition–enantioselective protonation approach toward tryptophans. Pracejus’s enantioselective addition of benzylmercaptan to α-aminoacrylate 20. Kumar and Dike’s enantioselective addition of thiophenol to α-arylacrylates. Tan’s enantioselective addition of aromatic thiols to 2

Synthesis of constrained analogues of tryptophan

• Elisabetta Rossi,
• Valentina Pirovano,
• Marco Negrato,
• Giorgio Abbiati and
• Monica Dell’Acqua

Beilstein J. Org. Chem. 2015, 11, 1997–2006, doi:10.3762/bjoc.11.216

• library of compounds bearing the free amino acid function at C-3 and pertaining to the class of constrained tryptophan analogues. Keywords: constrained tryptophans; Diels–Alder; indoles; tetrahydrocarbazoles; unnatural amino acids; Introduction With the term of “unnatural” amino acids, a plethora of

Synthesis of 2-substituted tryptophans via a C3- to C2-alkyl migration

• Michele Mari,
• Simone Lucarini,
• Francesca Bartoccini,
• Giovanni Piersanti and
• Gilberto Spadoni

Beilstein J. Org. Chem. 2014, 10, 1991–1998, doi:10.3762/bjoc.10.207

• (Dha) derivatives under Lewis acid-mediated conditions has been investigated. The formation of 2-substituted tryptophans is proposed to occur through a selective alkylative dearomatization–cyclization followed by C3- to C2-alkyl migration and rearomatization. Keywords: Dehydroalanine; Friedel–Crafts

• alkylation; indoles; migration; tryptophans; Introduction Facile access to tryptophan and unnatural tryptophan derivatives is of general interest because tryptophans are found in many naturally occurring compounds and are an important component of biologically active compounds [1][2][3][4][5][6][7

• degradation and modification [18][19][20][21][22][23][24][25]. As part of our ongoing research on the use of the unsaturated amino acid dehydroalanine (Dha) in organic synthesis [26][27][28][29][30][31][32][33][34][35][36][37], we have focused our attention on the syntheses of tryptophans, cyclo-tryptophans

Control of stilbene conformation and fluorescence in self-assembled capsules

• Mark R. Ams,
• Dariush Ajami,
• Stephen L. Craig,
• Jye-Shane Yang and
• Julius Rebek Jr

Beilstein J. Org. Chem. 2009, 5, No. 79, doi:10.3762/bjoc.5.79

• antibody interior [2][3][4], recent studies show that nearby tryptophans can transfer electrons to the stilbene excited state and an intense blue fluorescence develops. Inside the tight-fitting capsule 1.1 [5][6] (Figure 1) where it is surrounded by 16 aromatic panels, trans-stilbene’s fluorescence is