Genome mining of labdane-related diterpenoids: Discovery of the two-enzyme pathway leading to (−)-sandaracopimaradiene in the fungus Arthrinium sacchari

• Fumito Sato,
• Terutaka Sonohara,
• Shunta Fujiki,
• Akihiro Sugawara,
• Yohei Morishita,
• Taro Ozaki and
• Teigo Asai

Beilstein J. Org. Chem. 2024, 20, 714–720, doi:10.3762/bjoc.20.65

• complexity. TCs are generally classified into two main classes, class I and class II. Class I TCs initiate the cyclization by heterolytic cleavage of substrates to generate a diphosphate anion and an allylic carbocation, and class II enzymes start cyclization by protonating a double bond or an epoxide

Production of non-natural 5-methylorsellinate-derived meroterpenoids in Aspergillus oryzae

• Jia Tang,
• Yixiang Zhang and
• Yudai Matsuda

Beilstein J. Org. Chem. 2024, 20, 638–644, doi:10.3762/bjoc.20.56

• strong inosine 5-monophosphate dehydrogenase inhibitor [6]. The biosynthesis of fungal meroterpenoids has garnered interest in the organic chemistry field due to their structural complexity and associated intriguing enzymatic reactions and has thus been extensively researched for over a decade, providing

Introduction of a human- and keyboard-friendly N-glycan nomenclature

• Friedrich Altmann,
• Johannes Helm,
• Martin Pabst and
• Johannes Stadlmann

Beilstein J. Org. Chem. 2024, 20, 607–620, doi:10.3762/bjoc.20.53

• an ultimate solution to this dilemma as we think it is not yet time to impose another layer of complexity onto the herein proposed model. On top, automatic converters will encounter difficulties with such side rules. Nevertheless, for “domestic needs” shall four options be presented (Scheme 1

Switchable molecular tweezers: design and applications

• Pablo Msellem,
• Maksym Dekthiarenko,
• Nihal Hadj Seyd and
• Guillaume Vives

Beilstein J. Org. Chem. 2024, 20, 504–539, doi:10.3762/bjoc.20.45

• that no new atoms are introduced into the molecule, thus ensuring first-order kinetics of the process without complexity. One of the possible mechanisms of redox-induced switching involves an intramolecular bond formation that introduces non-covalent interactions between tweezers endpoints leading to a

Ligand effects, solvent cooperation, and large kinetic solvent deuterium isotope effects in gold(I)-catalyzed intramolecular alkene hydroamination

• Ruichen Lan,
• Brock Yager,
• Yoonsun Jee,
• Cynthia S. Day and
• Amanda C. Jones

Beilstein J. Org. Chem. 2024, 20, 479–496, doi:10.3762/bjoc.20.43

• solvent and anion effects add complexity to mechanistic interpretation, and the reluctance of alkylgold complexes to undergo protodeauration under similar conditions give us pause [28]. While computational studies support protodeauration, the significantly lower reactivity of alkenes compared to alkynes

Mechanisms for radical reactions initiating from N-hydroxyphthalimide esters

• Carlos R. Azpilcueta-Nicolas and
• Jean-Philip Lumb

Beilstein J. Org. Chem. 2024, 20, 346–378, doi:10.3762/bjoc.20.35

• reaction classes, we discuss the utility of the NHPI esters, with an eye towards their continued development in complexity-generating transformations. Keywords: decarboxylative couplings; mechanisms; NHPI-esters; radical reactions; Introduction The historical challenges of using radicals in synthetic

• stoichiometric electron donors, the presence of a TM catalyst, the formation of a charge-transfer complex, and the overall reaction conditions. While we hope that this discussion will spur the continued development of NHPI esters in complexity-generating transformations, it is not comprehensive, and we refer

Catalytic multi-step domino and one-pot reactions

• Svetlana B. Tsogoeva

Beilstein J. Org. Chem. 2024, 20, 254–256, doi:10.3762/bjoc.20.25

• atom efficiency, step and pot economies, decreased number of purification steps, or protecting-group-free synthesis. Multi-step domino [1][2] and one-pot [3] reactions represent a new powerful toolbox in organic synthesis to install molecular complexity economically and sustainably, starting from

Photochromic derivatives of indigo: historical overview of development, challenges and applications

• Gökhan Kaplan,
• Zeynel Seferoğlu and
• Daria V. Berdnikova

Beilstein J. Org. Chem. 2024, 20, 228–242, doi:10.3762/bjoc.20.23

• new level of complexity and promise. The photochromic indigos represent a relatively rare type of visible-light-responsive T-type photoswitches demonstrating negative photochromism. The absorption of the photoswitchable indigos covers the spectral range from green to NIR light (≈550–700 nm) making

Synthesis of the 3’-O-sulfated TF antigen with a TEG-N₃ linker for glycodendrimersomes preparation to study lectin binding

• Mark Reihill,
• Hanyue Ma,
• Dennis Bengtsson and
• Stefan Oscarson

Beilstein J. Org. Chem. 2024, 20, 173–180, doi:10.3762/bjoc.20.17

• to analyse when data were recorded in CDCl3. Changing the NMR solvent to CD3OD greatly reduced the complexity of the spectra [21][22][23]. Since 7 possessed an azido group as part of the linker, removal of the Troc group under reductive conditions was ruled out due to probable chemoselectivity issues

Perspectives on push–pull chromophores derived from click-type [2 + 2] cycloaddition–retroelectrocyclization reactions of electron-rich alkynes and electron-deficient alkenes

• Michio Yamada

Beilstein J. Org. Chem. 2024, 20, 125–154, doi:10.3762/bjoc.20.13

• multiple chromophore units induces complexity in the interpretation of the resulting circular dichroism (CD) spectra because of the overlap of several exciton couplets. Thus, exciton coupling CD signals were not discernible for 51–55. Further, regarding 56, the exciton coupling CD signal in the ICT region

Electron-beam-promoted fullerene dimerization in nanotubes: insights from DFT computations

• Laura Abella,
• Gerard Novell-Leruth,
• Josep M. Ricart,
• Josep M. Poblet and
• Antonio Rodríguez-Fortea

Beilstein J. Org. Chem. 2024, 20, 92–100, doi:10.3762/bjoc.20.10

• singlet state [10]. Although only a few analyses of the reaction mechanisms have been studied due to the complexity of the system, several intermediates inside the CNT have been proposed [3][11][12], which may be different from those proposed to take place in the gas phase or in the solid state at high

Optimizing reaction conditions for the light-driven hydrogen evolution in a loop photoreactor

• Pengcheng Li,
• Daniel Kowalczyk,
• Johannes Liessem,
• Mohamed M. Elnagar,
• Dariusz Mitoraj,
• Radim Beranek and
• Dirk Ziegenbalg

Beilstein J. Org. Chem. 2024, 20, 74–91, doi:10.3762/bjoc.20.9

• nitride; solar energy storage; Introduction The world is in the midst of the first truly global energy crisis with unprecedented breadth and complexity [1]. Meanwhile, the rise of the world’s population and economic growth demands more energy. Of all energy sources, fossil fuels have been dominating over

Studying specificity in protein–glycosaminoglycan recognition with umbrella sampling

• Mateusz Marcisz,
• Sebastian Anila,
• Margrethe Gaardløs,
• Martin Zacharias and
• Sergey A. Samsonov

Beilstein J. Org. Chem. 2023, 19, 1933–1946, doi:10.3762/bjoc.19.144

• complexity in decoding their sulfation pattern. Their charged nature necessitates the application of appropriate methods for electrostatics, ions, and solvent, particularly given their abundance in protein–GAG interfaces compared to complexes involving other classes of biomolecules. The periodicity can lead

• reflect the system's state under particular conditions with explicitly defined reaction coordinate values, the visualization of these continuous data potentially offers a more comprehensive insight into the complexity of the system related to its dynamic behavior within each window. Basic FGF Ligand 1

• potential of non-purely electrostatics dominance in the protein–GAG interactions. The more detailed analysis of the GAG recognition in this system in near-native states points out to the complexity of free energy landscape but at the same identifies the key charged H-bonding contributors to the GAG binding

Biphenylene-containing polycyclic conjugated compounds

• Cagatay Dengiz

Beilstein J. Org. Chem. 2023, 19, 1895–1911, doi:10.3762/bjoc.19.141

• ) [46]. This complexity arises from factors such as limited substrate versatility and the difficulty in incorporating solubilizing groups into the symmetric azaacene framework. In the initial stage, the condensation reactions between biphenylene-2,3-dione (52) and diaminothiadiazoles 55a,b resulted in

Active-metal template clipping synthesis of novel [2]rotaxanes

• Cătălin C. Anghel,
• Teodor A. Cucuiet,
• Niculina D. Hădade and
• Ion Grosu

Beilstein J. Org. Chem. 2023, 19, 1776–1784, doi:10.3762/bjoc.19.130

• , reported by Sauvage in 1983 [14], the synthetic strategies employed to access MIMs, including catenanes, rotaxanes and molecular knots, have grown in number and complexity of the obtained structures [15]. Thus, currently, synthesis of rotaxanes is usually performed through clipping, capping, snaping or

Functional characterisation of twelve terpene synthases from actinobacteria

• Anuj K. Chhalodia,
• Houchao Xu,
• Georges B. Tabekoueng,
• Binbin Gu,
• Kizerbo A. Taizoumbe,
• Lukas Lauterbach and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2023, 19, 1386–1398, doi:10.3762/bjoc.19.100

• ; biosynthesis; enzymes; NMR spectroscopy; terpenes; Introduction Terpene synthases are remarkable enzymes that can convert acyclic and achiral oligoprenyl pyrophosphates into terpene hydrocarbons or alcohols of high structural complexity. These enzymatic reactions are initiated by ionisation of the substrate

Non-noble metal-catalyzed cross-dehydrogenation coupling (CDC) involving ether α-C(sp³)–H to construct C–C bonds

• Hui Yu and
• Feng Xu

Beilstein J. Org. Chem. 2023, 19, 1259–1288, doi:10.3762/bjoc.19.94

• synthesis of compounds with quaternary centers and natural products with high structural complexity. In 2014, Li et al. reported a CuCl2-catalyzed cross-dehydrogenation coupling reaction of C(sp3)–H bonds adjacent to an ether oxygen and the C(sp3)–H bonds at the α-position of a carbonyl functionality in the

Acetaldehyde in the Enders triple cascade reaction via acetaldehyde dimethyl acetal

• Alessandro Brusa,
• Debora Iapadre,
• Maria Edith Casacchia,
• Alessio Carioscia,
• Giuliana Giorgianni,
• Giandomenico Magagnano,
• Fabio Pesciaioli and
• Armando Carlone

Beilstein J. Org. Chem. 2023, 19, 1243–1250, doi:10.3762/bjoc.19.92

• tool for achieving molecular complexity. Their synthetic potential has been demonstrated by their application in the total synthesis of complex natural compounds [2][4][9][10][11][12]. A remarkable example of an amino-catalyzed cascade process was reported by Enders [11], a three-component cascade

• increasing structural and stereochemical complexity starting from readily available substrates. The scope of the process was shown to be successful with aliphatic aldehydes 2, aromatic nitroalkenes 3, and both aromatic and aliphatic unsaturated aldehydes 4. Given our recent interest in the use of a surrogate

• . Although the scope is limited to aromatic nitroalkenes and enals, the yields are good considering the complexity of the domino process that involves highly reactive partners, and the ees are consistently very high. Finally, albeit there is low diastereocontrol, the diastereomers can be easily separated by

Enabling artificial photosynthesis systems with molecular recycling: A review of photo- and electrochemical methods for regenerating organic sacrificial electron donors

• Grace A. Lowe

Beilstein J. Org. Chem. 2023, 19, 1198–1215, doi:10.3762/bjoc.19.88

• -situ recycling of sacrificial donors and redox mediators would require less donor/mediator because the species would constantly be regenerated and not consumed. If the donor or mediator is stable under the reaction conditions, the cost and complexity of the donor can be higher than that of a

Photoredox catalysis harvesting multiple photon or electrochemical energies

• Mattia Lepori,
• Simon Schmid and
• Joshua P. Barham

Beilstein J. Org. Chem. 2023, 19, 1055–1145, doi:10.3762/bjoc.19.81

• , direct electrolytic reactions taking place at the heterogeneous interface presents an additional layer of complexity to mechanistic understanding and conferring selectivity. Nonetheless, SOE has enjoyed a dramatic rise in popularity in the last decade [24][25][26][27], partly driven by reactor

Linker, loading, and reaction scale influence automated glycan assembly

• Marlene C. S. Dal Colle,
• Manuel G. Ricardo,
• Nives Hribernik,
• José Danglad-Flores,
• Peter H. Seeberger and
• Martina Delbianco

Beilstein J. Org. Chem. 2023, 19, 1015–1020, doi:10.3762/bjoc.19.77

• increasing order of complexity, we prepared α-1,6-linked dimannosides (1,2) [32], branched trisaccharides (3,4) [12], and linear α-1,4-linked hexaglucosides (5,6) [15][33]. Each synthesis was performed with 6.5 equivalents of BB per glycosylation cycle using previously reported AGA conditions (see Supporting

Five new sesquiterpenoids from agarwood of Aquilaria sinensis

• Hong Zhou,
• Xu-Yang Li,
• Hong-Bin Fang,
• He-Zhong Jiang and
• Yong-Xian Cheng

Beilstein J. Org. Chem. 2023, 19, 998–1007, doi:10.3762/bjoc.19.75

• more active than alcohols or acids. Conclusion In summary, five new eudesmane-type sesquiterpenes compounds (1–5) and five known compounds (6–10) were isolated from agarwood of A. sinensis. The discovery of these new compounds enriches the structural diversity and complexity of sesquiterpenes derived

Aromatic C–H bond functionalization through organocatalyzed asymmetric intermolecular aza-Friedel–Crafts reaction: a recent update

• Anup Biswas

Beilstein J. Org. Chem. 2023, 19, 956–981, doi:10.3762/bjoc.19.72

• acyclic, carbocyclic, heterocyclic, and polycyclic molecular architectures with high molecular complexity. In particular, asymmetric organocatalysis plays a pivotal role in the construction of optically active, bioactive, and natural products. The main advantages of organocatalyzed stereoselective

Eschenmoser coupling reactions starting from primary thioamides. When do they work and when not?

• Lukáš Marek,
• Jiří Váňa,
• Jan Svoboda and
• Jiří Hanusek

Beilstein J. Org. Chem. 2023, 19, 808–819, doi:10.3762/bjoc.19.61

• amount and strength of the external base. Conclusion Our study corroborates the complexity of the reaction between α-bromolactams/α-bromoamides and primary thioamides represented by thiobenzamide and thioacetamide. The appearance and significance of individual intermediates which are decisive for the

Enolates ambushed – asymmetric tandem conjugate addition and subsequent enolate trapping with conventional and less traditional electrophiles

• Péter Kisszékelyi and
• Radovan Šebesta

Beilstein J. Org. Chem. 2023, 19, 593–634, doi:10.3762/bjoc.19.44

• α,β-unsaturated carbonyl compounds [2]. In particular, the last-mentioned method is highly synthetically relevant. This approach has the advantage of being more selective and affording more molecular complexity in one step. In addition, transition-metal catalysis allows the introduction of