Electrochemical reduction of unsaturated carbon–carbon bonds via 3d transition-metal catalysis

• Geon Kang,
• Minki Jeon,
• Pooja Kumari Jat,
• Cheoljae Kim and
• Isaac Choi

Beilstein J. Org. Chem. 2026, 22, 955–981, doi:10.3762/bjoc.22.75

• indicated that protonation of low-valent cobalt species leads to the formation of a Co(III)–H intermediate [95], which then reacts with the alkyne to regenerate the monoligated Co(II) catalyst (Scheme 3D). DFT calculations further support that proton delivery from HFIP to the cobalt–alkyne adduct proceeds

• precede a kinetically relevant proton/electron delivery event (Scheme 4C). DFT calculations proved a hydride-free, multisite proton-coupled electron transfer (MS-PCET) manifold [66][67][98], in which Cp2Co mediates electron transfer to an acid- and alkyne-associated cobalt intermediate, followed by acid

• revealed the emergence of new absorption features upon alkyne addition, consistent with the formation of a vinyl–Co(III) intermediate. DFT calculations further demonstrated that variation of the salen ligand framework modulates the Co–C bond-dissociation energy (BDE) of the vinyl–cobalt intermediate

Recent advances in copper-catalyzed direct hydroamination of alkenes with (hetero)aromatic amines

• Hyejeong Lee and
• Yunmi Lee

Beilstein J. Org. Chem. 2026, 22, 925–947, doi:10.3762/bjoc.22.73

• , particularly for ester-substituted alkenes. Mechanistic insights obtained from the DFT calculations suggested that the reaction proceeded via a copper–amido catalytic cycle involving metal-assisted olefin activation and the aminocupration pathway. In the initial step, deprotonation of the amine by KOt-Bu

Cascade transformation of 2-(diazoacetyl)-2H-azirines to 2-aroyl-3-hydroxy-1H-pyrroles via condensation with aromatic aldehydes

• Timur O. Zanakhov,
• Ekaterina E. Galenko,
• Mikhail S. Novikov and
• Alexander F. Khlebnikov

Beilstein J. Org. Chem. 2026, 22, 897–904, doi:10.3762/bjoc.22.70

• , to our knowledge, no derivative of trans-2-oxa-7-azabicyclo[4.1.0]heptane has been prepared [25][26]. According to our DFT calculations, trans-2-oxa-7-azabicyclo[4.1.0]heptane has a 42.6 kcal/mol higher Gibbs energy than the cis isomer, and the introduction of two sp2-hybridized carbons, as in

• formed (≈90%), while the minor one, based on the arguments presented above, is apparently the (1RR,3RR,6RR)-isomer. To shed light on the mechanism and stereoselectivity of the reaction, DFT calculations were performed at the B3LYP-D3/6-311+G(d,p)/LANL2DZ(Cs) level of theory with a SMD solvent model (for

• , which was confirmed by DFT calculations at the B3LYP-D3/6-311+G(d,p) level of theory with a SMD solvent model for MeCN. According to the calculations, the aziridine ring of protonated intermediate D readily opens to form the more stable cation E. The intramolecular H-shift leading to the ammonium cation

The trans-influence in gold chemistry from a catalytic perspective

• Manfred Bochmann

Beilstein J. Org. Chem. 2026, 22, 838–856, doi:10.3762/bjoc.22.66

• of Pt–CO. Bonding analysis of these CO complexes indicates mainly σ-donation but little back-donation, with donation/back-donation (d/b) ratios much larger than in the comparable Pt(II) complex [(C^N^N)Pt–CO]+. DFT studies found no evidence for π-bonding contributions to the Au–CO bond in the highest

• complexes. Both terminal and internal alkynes could be inserted, with a wide variety of functional groups including alkyl, aryl, OH, COOH, amide and aldehyde substituents, but not DMAD. The excellent stereo- and regiochemical selectivity could be explained by a bimolecular mechanism, as confirmed by DFT

• optimised by DFT calculations [82]. They clearly fall into two categories: In the C^N and P^N compounds the allyl bonding is very asymmetrical, with a long and a short C–C bond and strong variations in Au–C bond distances, as expected for a σ,π-allyl, while in 27 and its methallyl analogue the bonding is

Halogenated azobenzene acrylates: from efficient solution photoswitching to stable solid-state photochromic materials

• Martina Vachtlová,
• Michaela Fecková,
• Vítězslav Zima,
• Jan Podlesný,
• Milan Klikar,
• Oldřich Pytela,
• Patrik Pařík,
• Jakub Opršal,
• Eliška Juhaňáková,
• Veronika Chrtová and
• Filip Bureš

Beilstein J. Org. Chem. 2026, 22, 782–794, doi:10.3762/bjoc.22.60

• calorimetry (DSC), thermogravimetric analysis (TGA), cyclic voltammetry (CV), UV–vis absorption spectroscopy, 1H and 13C NMR, and theoretical DFT calculations were employed. Furthermore, the target compounds are designed for incorporation as photoactive copolymers into the structure of functionalized

• (DCE) containing 0.1 M Bu4NPF6 in a three-electrode cell by cyclic voltammetry (CV). The recorded peak potentials are given vs Ag/AgCl reference electrode (SSCE). The acquired electrochemical data obtained in DCE are summarized in Table 2 including DFT-calculated values while the corresponding HOMO

• corroborated by DFT results calculated for both isomers (Table 2). The highest HOMO–LUMO gap was measured/calculated for the dichloro derivative 1d, while the monosubstituted ones (1a, c and e) possess the narrowest ΔE values. As expected, the calculations further indicate the lower HOMO/LUMO energies/gaps for

Rongalite addition to dienones: diastereoselectivity in cyclic sulfone synthesis; stereochemical rationalization and prospects as a general conjugate nucleophile

• Melina Goga,
• Hao Zong,
• James Franco,
• Jazmine Prana,
• Rudolph Michel,
• Antonia Muro,
• Elana Rubin,
• Janet Brenya,
• Henk Eshuis and
• Magnus W. P. Bebbington

Beilstein J. Org. Chem. 2026, 22, 742–752, doi:10.3762/bjoc.22.56

• product, we used density functional theory (DFT) and conformational search techniques based on tight-binding methods to find the energetically minimized structure of 7 (see Supporting Information File 1 for details on all computations). The lowest energy structure is depicted in Figure 3. It shows a

Synthesis of heterocycles based on azomethine ylides from α-amino acids (or amines) and carbonyl compounds

• Ekaterina V. Berezhnaya,
• Alexander I. Ponyaev,
• Vitali M. Boitsov and
• Alexander V. Stepakov

Beilstein J. Org. Chem. 2026, 22, 705–741, doi:10.3762/bjoc.22.55

• , maleimides, alkenyl sulfones, β-nitrostyrene, chalcone, acrylonitrile, N,N-dimethylacrylamide, and N-acryloyloxazolidin-2-one. Using computational density functional theory (DFT), the authors concluded that the diastereoselectivity of the reaction is influenced by the size of the ligand, the presence or

• -quinolyl, 2-pyridyl, and 4-pyridyl fragments. It is worth noting that 1-(4-nitrophenyl)-1,3-butadiene (40) and 1,1-bis(2-pyridyl)ethylene (41) also proved to be suitable substrates in this reaction (Scheme 20). It was demonstrated by computational methods (DFT) that electronic effects within the

• efficient synthesis of a series of polysubstituted enantioenriched pyrrolidine derivatives 48 possessing a spiroindene molecular structure (Scheme 22) [59]. Based on the results of DFT calculations, it was suggested that the [6 + 3] cycloaddition product for benzofulvene 47 loses aromatic stability and

Photoorganocatalytic trifluoromethylation of (het)arenes in green conditions

• Egor N. Boronin,
• Svetlana E. Kaurkina,
• Milena M. Svetlakova,
• Anton S. Bolshakov,
• Maxim V. Arsenyev,
• Vasilii F. Otvagin,
• Alexey Yu. Fedorov,
• Timothy Noël and
• Alexander V. Nyuchev

Beilstein J. Org. Chem. 2026, 22, 662–671, doi:10.3762/bjoc.22.50

• reaction displays pronounced sensitivity to substituent patterns rather than electronic effects. Mechanistic investigations, including radical trapping, Stern–Volmer analysis, and DFT calculations, support a reductive quenching pathway involving photocatalyst-mediated reduction of TFAA. The protocol is

• TFAA is thermodynamically favorable (ΔE = 0.18 V), whereas the oxidation of TMB is disfavored (ΔE = −0.34 V). We next assessed the theoretical feasibility of the proposed mechanism by means of DFT and TDDFT calculations. The results revealed that the reduction of TFAA, followed by the generation of the

• that the addition of the electrophilic CF3 radical to the aromatic ring may differ in energetic profile between the two substrates (Scheme 5). However, DFT calculations showed that the thermodynamic parameters for both processes are comparable, indicating that other elementary steps may be responsible

Computational prediction of C–H hydricities and their use in predicting the regioselectivity of electron-rich C–H functionalisation reactions

• Rasmus M. Borup,
• Nicolai Ree and
• Jan H. Jensen

Beilstein J. Org. Chem. 2026, 22, 603–610, doi:10.3762/bjoc.22.46

• that evaluates the accuracy of different levels of theory, ranging from semiempirical methods (xTB [16]), composite electronic structure methods (r2SCAN-3c [19]) to DFT methods (M06-2X[21], CAM-B3LYP [22][23]). All methods are evaluated either as single-point calculations or optimization and frequency

• /anthracene-like cases as discussed in section 2 in Supporting Information File 1. We thus expect the DFT predictions to be significantly more accurate than the reported error, especially for chemically similar groups. Note that the linear scaling parameters derived from these experimental values do not

Experimental and DFT studies on the regioselective methanolysis of 5-azido-9-oxabicyclo[6.1.0]nonan-4-yl 4-nitrobenzoate isomers

• İlknur Polat,
• Selçuk Eşsiz and
• Emine Salamci

Beilstein J. Org. Chem. 2026, 22, 547–556, doi:10.3762/bjoc.22.40

• epoxide ring and acetylation resulted in the formation of two corresponding chloro-acetate isomers. The structure of one of the chloro-acetate isomers was determined via crystallographic analysis and the other by 1D and 2D NMR spectroscopy. DFT computations confirm the regioselectivity of the methanolysis

• process, highlighting its precision and efficiency. Keywords: azides; 8-azidocyclooct-4-en-1-yl 4-nitrobenzoate; DFT; epoxycyclooctane azide; methanolysis; Introduction Organic azides are very important precursors for the preparation and synthesis of various nitrogen-containing compounds, as well as

• formation mechanisms of the products yielded from the methanolysis of isomeric epoxides 9, we performed a series of density functional theory (DFT) computations using the software Gaussian 16 [26]. For this, geometry optimizations and harmonic vibrational frequency computations for the structures considered

Synthesis and uranyl(VI) extraction performance of a calix[4]pyrrole–tetrahydroxamic acid receptor

• Sara Karnib,
• Rana Baydoun,
• Wissam Zaidan,
• Nancy AlHaddad,
• Omar El Samad,
• Bilal Nsouli,
• Francine Cazier-Dennin and
• Pierre-Edouard Danjou

Beilstein J. Org. Chem. 2026, 22, 486–494, doi:10.3762/bjoc.22.36

• relevant example is a calix[6]arene functionalized with three hydroxamic acid groups, where a theoretical study using density functional theory (DFT) calculations showed that the complex with the uranyl is most stabilized when only two of the three hydroxamic acid units participate in binding [78]. This

Synthesis and stereochemical analysis of dynamic planar chiral oxa[7]orthocyclophene

• Yukiho Hashimoto,
• Yuuya Kawasaki,
• Kazunobu Igawa and
• Katsuhiko Tomooka

Beilstein J. Org. Chem. 2026, 22, 436–442, doi:10.3762/bjoc.22.30

• . The CD spectrum of 1ab showed a weak positive Cotton effect around 270 nm and a strong Cotton effect around 230 nm, and that of 1ad showed a weak negative Cotton effect around 290 nm and a strong Cotton effect around 250 nm. Each TD-DFT calculations for (R)-1ab and (R)-1ad showed good agreement in

• : 254 nm): a1), a2) chromatograms monitored at 254 nm; b1), b2) CD spectrum of the first eluates in a flow cell; c1), c2) calculated CD spectra using TD-DFT calculations at the B3LYP level using the 6-311G(2d,2p) basis set for C, H, and O atoms and the SDD basis set with the corresponding effective core

• procedures, characterization data, copies of 1H and 13C NMR spectra, and optimized geometries of DFT calculations. Supporting Information File 26: Crystallographic information file of compound 1ac. Acknowledgements We thank K. Imamura (Evaluation center of material properties, IMCE Kyushu University) for

Synthesis and anti-cancer activity of naphthalimide–organylselanyl conjugates

• Rajkumar Ravi and
• Selvakumar Karuthapandi

Beilstein J. Org. Chem. 2026, 22, 416–435, doi:10.3762/bjoc.22.29

• analyses, and structure and electronic properties were further investigated using density functional theory (DFT) calculations. Cytotoxicity tests were used to assess the anticancer potential of both conjugates, and it was found that both compounds showed notable activity against the test MDA-MB-231 breast

• characteristics and electronic properties of compounds 7 and 8, geometry optimisations and frequency calculations were performed using density functional theory (DFT) with the B3LYP functional and the 6-31G(d,p) basis set, as shown in Figure 3 [56][57]. The input structure of compound 7 was obtained from a single

• and 3.084 eV for compound 8 based on their experimental absorption wavelengths. Compound 7 (3.098 eV) and compound 8 (3.048 eV) DFT-calculated HOMO–LUMO energy gaps agree well with the energy values obtained through experimentation. Mulliken charge analysis (MCA) of the compounds 7 and 8 The MCA of

Electrosynthetic access to unsymmetrical oxaza[8]helicenes with high chiral stability and strong circularly polarized luminescence (CPL)

• Tin Zar Aye,
• Rubal Sharma,
• Muthu Karuppasamy,
• Daiya Suzuki,
• Haruka Nakajima,
• Yoshitane Imai,
• Mitsuhiro Arisawa,
• Mohamed S. H. Salem and
• Shinobu Takizawa

Beilstein J. Org. Chem. 2026, 22, 372–382, doi:10.3762/bjoc.22.25

• products were detected under the optimized conditions (Scheme 2). Based on our previous reports [48][56], DFT calculations, and cyclic voltammetry (CV) analyses (Figure 1), anodic single-electron transfer (SET) is expected to occur first from 3, generating the electrophilic radical cation [3]·+ as 3 (Eox

• [8]helicenes 5a and 5b, we performed DFT calculations to locate the transition states with the highest Gibbs free energies. In both cases, the transition states correspond to conformations in which the terminal rings adopt a face-to-face arrangement along the helical axis (Figure 3). The calculated

• insight into the electronic transitions, we performed time-dependent DFT (TD-DFT) calculations for all oxaza[7]helicenes 6 and oxaza[8]helicenes 5 after geometry optimization at the S1 minimum (see Supporting Information File 1 and Supporting Information File 2) [62][63]. The convergence of these

Recent advances in the cleavage of non-activated amides

• Eun-Sol Choi and
• Hyo-Jun Lee

Beilstein J. Org. Chem. 2026, 22, 352–369, doi:10.3762/bjoc.22.23

• restored after recalcination prior to reuse. Based on DFT calculations, the authors proposed that octanol is deprotonated and coordinated to Ce, while the amide substrate is simultaneously activated electrophilically through coordination to the Ce center (A). This dual activation enables the lattice oxygen

• transition-metal-catalyzed asymmetric C–H activation reactions as a directing group, thus necessitating an efficient method for the cleavage of 8-aminoquinoline-derived amides. The role of Me2SO4 in this transformation was elucidated through DFT calculations. Methylation of the carbonyl oxygen by Me2SO4

• bioactive compounds underwent smooth esterification with TFE to give the corresponding 2,2,2-trifluoroethyl esters 82–85 in high yields. To elucidate the reaction mechanism, cyclic voltammetry experiments, control reactions, and DFT calculations were conducted. At the anode, bromide ions are oxidized to

Spirobarbiturates with a pyrrolizidine moiety: synthesis, structure and biological evaluation

• Arthur A. Puzyrkov,
• Andrew S. Drachuk,
• Ekaterina A. Popova,
• Alexander V. Stepakov and
• Vitali M. Boitsov

Beilstein J. Org. Chem. 2026, 22, 274–288, doi:10.3762/bjoc.22.20

• formation of azomethine ylide from alloxan (1) and ʟ-proline (2) was previously studied using DFT calculations [43]. Based on the calculated data, it was assumed that the 1,3-dipole is formed as a result of a multistage sequence: initial generation of a zwitterionic imine intermediate from 1 and 2, followed

Conformational analysis of difluoromethylornithine: factors influencing its gas-phase and bioactive conformations

• Matheus P. Freitas

Beilstein J. Org. Chem. 2026, 22, 237–243, doi:10.3762/bjoc.22.17

• the cc-pVTZ and cc-pVQZ basis sets. Natural bond orbital (NBO) analyses [12] were also performed at the same DFT level, employing the NBO7DEL, LEWIS, and STERIC keywords to suppress electron-delocalization effects and thereby quantify the contributions of Lewis- and non-Lewis-type interactions to the

• amino acid residues and water molecules, while the ligand is delineated by a contour line to distinguish it from the binding cavity. Lowest-energy type-I, type-II, and type-III conformers of the zwitterionic form of (S)-DFMO. Color labels: H = blue, C = pink, N = orange, O = red, F = yellow. DFT

Configuration–packing synergy enabling integrated crystalline-state RTP and amorphous-state TADF

• Ruiyan Wang and
• Yunan Wu

Beilstein J. Org. Chem. 2026, 22, 224–236, doi:10.3762/bjoc.22.16

• photophysical properties of 1, particularly its ability to exhibit RTP at room temperature. TD-DFT (time-dependent density functional theory) calculations were carried out to explore and analyze the theoretical structure and electronic properties of the compound. These calculations provided valuable insights

• Shimadzu TGA-50 analyzer. Differential scanning calorimetry (DSC) was carried out on a NETZSCH DSC-204 instrument. All calculations were carried out using Gaussian 09. Ground-state geometries were optimized by DFT at the B3LYP/6-31G(d) level. Frequency calculations at the same level confirmed that the

• optimized structures correspond to true minima (no imaginary frequencies). Vertical excitation energies were computed by TD-DFT at the B3LYP/6-31G(d) level based on the optimized geometries. Electroluminescent devices were fabricated with a conventional multilayer OLED structure using ITO-coated glass

Improved synthesis and physicochemical characterization of the selective serotonin 2A receptor agonist 25CN-NBOH

• Adrian G. Rossebø,
• Hannah G. Kolberg,
• Anders E. Tønder,
• Louise Kjaerulff,
• Poul Erik Hansen,
• Karla A. Frydenvang,
• Jesper Østergaard and
• Jesper L. Kristensen

Beilstein J. Org. Chem. 2026, 22, 175–184, doi:10.3762/bjoc.22.11

• be partially responsible for its high membrane permeability. To investigate if an IMHB is indeed present in 1, we combined DFT calculations with NMR spectroscopy titrations. For a system containing an IMHB, it would be expected that replacing the proton (O–H) with a deuteron (O–D) would lead to an

• isotope effect observable as changes in the 13C NMR chemical shift [18][19]. DFT calculations were based on a truncated model (Figure 6a) containing the essential elements for intramolecular hydrogen bonding. The structure was considered both in vacuum as well as with DMSO or water as implicit solvents

• and 0.1% phosphoric acid in the ratios 35:65 and 25:75, v/v for the distribution coefficient and stability experiments, respectively. The ChemStation software (Version B.04.03, Agilent Technologies) was used for instrument control and data collection. Computational chemistry DFT calculations were

Design and synthesis of an axially chiral platinum(II) complex and its CPL properties in PMMA matrix

• Daiki Tauchi,
• Sota Ogura,
• Misa Sakura,
• Kazunori Tsubaki and
• Masashi Hasegawa

Beilstein J. Org. Chem. 2026, 22, 143–150, doi:10.3762/bjoc.22.7

• chiral platinum(II) complex was synthesized via Sonogashira coupling and subsequent coordination of a pincer ligand to a precursor. The complex exhibited a broad absorption band ranging from 250 to 550 nm in the UV–vis spectrum, with TD-DFT calculations indicating mixed ligand-to-ligand charge transfer

• behavior, through a combination of experimental measurements and density functional theory (DFT) calculations. The experimental UV–vis spectrum was in good agreement with the DFT calculations, revealing that the electronic transitions originate from both ligand-to-ligand charge transfer (LL’CT) and metal

• spectroscopy, as well as high-resolution mass spectrometry (HRMS). Due to its low solubility, single crystals suitable for X-ray crystallographic analysis could not be obtained. Spectroscopic analysis and DFT calculations To elucidate the electronic structure of the platinum(II) complex, UV–vis absorption

Symmetrical D–π–A–π–D indanone dyes: a new design for nonlinear optics and cyanide detection

• Ergin Keleş,
• Alberto Barsella,
• Nurgül Seferoğlu,
• Zeynel Seferoğlu and
• Burcu Aydıner

Beilstein J. Org. Chem. 2026, 22, 131–142, doi:10.3762/bjoc.22.6

• theory (DFT) methods. The dyes also exhibit chemosensor properties, showing selectivity for cyanide via a Michael addition mechanism that causes the disappearance of the ICT band, and a significant color change was observed in both organic and aqueous media. In addition, the interaction mechanism between

• cyanide and the chemosensor is determined by a 1H NMR study and explained by DFT calculations. Keywords: chemosensor; DFT calculations; donor–π–acceptor–π–donor based organic dyes; indan-2-one; NLO; Introduction Over the past decades, the functional heterocyclic push–pull dyes have attracted significant

• functional theory (DFT) and time-dependent DFT (TD-DFT) calculations, which were consistent with experimental results. NLO properties of the compounds were experimentally determined using the EFISH method and calculated using theoretical methods. Additionally, the thermal decomposition temperatures, an

Advances in Zr-mediated radical transformations and applications to total synthesis

• Hiroshige Ogawa and
• Hugh Nakamura

Beilstein J. Org. Chem. 2026, 22, 71–87, doi:10.3762/bjoc.22.3

• for the success of the reaction. DFT calculations suggested that in the transition state (TS1), a Cl–π interaction between the chlorine atom on the zirconocene catalyst and the aromatic ring of the substrate facilitated rapid halogen atom transfer (XAT), generating a radical at the C3 position of

• potential and stabilizing the radical pathway. The DFT calculations are shown in Scheme 13A. The activation barrier for the XAT process was calculated to be ΔG‡ = 8.0 kcal/mol, indicating that this process can proceed spontaneously around room temperature. Moreover, the transition state (TS1) suggested the

Sustainable electrochemical synthesis of aliphatic nitro-NNO-azoxy compounds employing ammonium dinitramide and their in vitro evaluation as potential nitric oxide donors and fungicides

• Alexander S. Budnikov,
• Nikita E. Leonov,
• Michael S. Klenov,
• Andrey A. Kulikov,
• Igor B. Krylov,
• Timofey A. Kudryashev,
• Aleksandr M. Churakov,
• Alexander O. Terent’ev and
• Vladimir A. Tartakovsky

Beilstein J. Org. Chem. 2025, 21, 2739–2754, doi:10.3762/bjoc.21.211

• end of the reaction), which is sufficient to oxidize ADN. According to the performed calculations, competitive oxidation of 1a does not occur, which is confirmed by the obtained CV-data (see Figure 1 and Figure 2). According to DFT calculations, the reaction of N-radical A with 2-nitro-2

• spectroscopy using 1,1,2,2-tetrachloroethane as an internal standard. Computational details: DFT computations were performed for 1 atm. and 298.15 K in Orca 6.1.0 package [93]. Results were visualized in Chemcraft 1.8 program. For conformationally flexible structures, generation of conformational ensembles was

Mechanistic insights into hydroxy(tosyloxy)iodobenzene-mediated ditosyloxylation of chalcones: a DFT study

• Jai Parkash,
• Sangeeta Saini,
• Vaishali Saini,
• Omkar Bains and
• Raj Kamal

Beilstein J. Org. Chem. 2025, 21, 2703–2715, doi:10.3762/bjoc.21.208

• DFT study shows that the three-membered cyclic carbocation is not formed (Scheme 3). Therefore, to obtain β,β-ditosyloxy ketones as products from such chalcones, the possible mechanism is that, in Int3 the tosyloxy group at β-position donates electrons and the negatively charged aryl group is released

Recent advancements in the synthesis of Veratrum alkaloids

• Morwenna Mögel,
• David Berger and
• Philipp Heretsch

Beilstein J. Org. Chem. 2025, 21, 2657–2693, doi:10.3762/bjoc.21.206

• -NOESY and DFT calculations. The tertiary amine was masked as the hydrochloride salt with concomitant ketal deprotection, which was followed by hydrogenation to remove the benzyl protecting group to obtain (±)-4-methylenegermine hydrochloride (17·HCl) in 31 steps (LLS from commercial materials) and an