Diastereoselective auxiliary- and catalyst-controlled intramolecular aza-Michael reaction for the elaboration of enantioenriched 3-substituted isoindolinones. Application to the synthesis of a new pazinaclone analogue

• Romain Sallio,
• Stéphane Lebrun,
• Frédéric Capet,
• Francine Agbossou-Niedercorn,
• Christophe Michon and
• Eric Deniau

Beilstein J. Org. Chem. 2018, 14, 593–602, doi:10.3762/bjoc.14.46

• -transfer catalyst; 3-substituted isoindolinones; Introduction Isoindolinones I (Figure 1), e.g., 2,3-dihydro-1H-isoindol-1-ones, also called phthalimidines are bicyclic lactams whose molecular structure is the basis of a wide range of alkaloids and biologically active compounds [1][2][3][4][5][6][7][8][9

• -substituted isoindolinones 1 and 2 could be obtained in high enantioselectivities from the intermediates (2R,3S)-3–5 after removal of the chiral auxiliary (Scheme 1). (2R,3S)-bicyclic lactams 3–5 could be prepared by the asymmetric intramolecular organo-catalyzed aza-Michael reaction of (R)-benzamides 6–8

Structure–property relationships and third-order nonlinearities in diketopyrrolopyrrole based D–π–A–π–D molecules

• Jan Podlesný,
• Lenka Dokládalová,
• Oldřich Pytela,
• Adam Urbanec,
• Milan Klikar,
• Numan Almonasy,
• Tomáš Mikysek,
• Jaroslav Jedryka,
• Iwan V. Kityk and
• Filip Bureš

Beilstein J. Org. Chem. 2017, 13, 2374–2384, doi:10.3762/bjoc.13.235

• , diketopyrrolopyrroles (DPP) represent an unique class of organic molecules based on central, fused, and conjugated bicyclic lactams of 2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione. After its serendipitous discovery by Farnum et al. in 1974 [1] and subsequent first applications as organic, insoluble, and high-performance

Tandem cross enyne metathesis (CEYM)–intramolecular Diels–Alder reaction (IMDAR). An easy entry to linear bicyclic scaffolds

• Javier Miró,
• María Sánchez-Roselló,
• Álvaro Sanz,
• Fernando Rabasa,
• Carlos del Pozo and
• Santos Fustero

Beilstein J. Org. Chem. 2015, 11, 1486–1493, doi:10.3762/bjoc.11.161

• 1–3). Comparable yields were obtained with either electron-donating or electron-withdrawing substituents in the starting alkyne 1 (Table 2, entries 4 and 5). In addition, 5- and 7-membered bicyclic lactams 3f and 3g were also synthesized in moderate yields (Table 2, entries 6 and 7). Again, all

Diastereoselective and enantioselective conjugate addition reactions utilizing α,β-unsaturated amides and lactams

• Katherine M. Byrd

Beilstein J. Org. Chem. 2015, 11, 530–562, doi:10.3762/bjoc.11.60

• outcome of the alkylation step. In fact, the observed diastereoselectivity of the alkylation step is in agreement with previous reports on the diastereoselective α-alkylation of amides using (S,S)-(+)-pseudoephedrine as a chiral auxiliary [49][50][57]. α,β-Unsaturated aminoalcohol-derived bicyclic lactams

The Shono-type electroorganic oxidation of unfunctionalised amides. Carbon–carbon bond formation via electrogenerated N-acyliminium ions

• Alan M. Jones and
• Craig E. Banks

Beilstein J. Org. Chem. 2014, 10, 3056–3072, doi:10.3762/bjoc.10.323

• proved difficult to determine the cis/trans relationship in many examples due to the presence of rotameric forms, however the products of phenyl magnesiumbromide were identified to be trans presumably due to opposite face attack of intermediate 52b. Bicyclic lactams [73] and tricyclic systems [74] have

Isocyanide-based multicomponent reactions towards cyclic constrained peptidomimetics

• Gijs Koopmanschap,
• Eelco Ruijter and
• Romano V.A. Orru

Beilstein J. Org. Chem. 2014, 10, 544–598, doi:10.3762/bjoc.10.50

• stereoinduction was observed for the newly formed stereocenter (dr 1:1). As an extension, the authors performed the Ugi reaction with allyl amine 79 and olefinic amino acids 78 (derived from pyroglutamic acid), that, after a following ring-closure-metathesis (RCM) with Grubb’s catalyst, resulted in bicyclic

• lactams (81, 46% over the two steps, Scheme 24). In addition, an even shorter route by utilizing three olefinic Ugi-substrates was also reported. Herein, the ring closing step included a double RCM and resulted in an equal amount of both products 83a and 83b (ratio 1:1) [75][76]. Triazoles The replacement

Tandem catalysis of ring-closing metathesis/atom transfer radical reactions with homobimetallic ruthenium–arene complexes

• Yannick Borguet,
• Xavier Sauvage,
• Guillermo Zaragoza,
• Albert Demonceau and
• Lionel Delaude

Beilstein J. Org. Chem. 2010, 6, 1167–1173, doi:10.3762/bjoc.6.133

• a diastereomeric mixture of unsaturated bicyclic lactams 11 (Table 3, entry 2). The two products were separated by column chromatography. 2D NMR spectroscopy and mass spectrometry analyses confirmed that dehydrochlorination had occurred during the catalytic process. Further work is underway to

Synthesis of fluorinated δ-lactams via cycloisomerization of gem-difluoropropargyl amides

• Satoru Arimitsu and
• Gerald B. Hammond

Beilstein J. Org. Chem. 2010, 6, No. 48, doi:10.3762/bjoc.6.48

• difluorodihydropyridinones via a ring-closing metathesis reaction, and of 4,4-difluoro-3-oxoisoquinolines through a ring-closing metathesis–enyne metathesis tandem reaction. These products, in turn, undergo a Diels–Alder reaction to yield heterotricyclic systems in moderate to good yields. Keywords: bicyclic lactams