Helten Group


Publications



34. N. A. Riensch, A. Deniz, S. Kühl, L. Müller, A. Adams, A. Pich,* H. Helten,* Borazine-based inorganic—organic hybrid cyclomatrix microspheres by silicon/boron exchange precipitation polycondensation, Polym. Chem. 2017, DOI: 10.1039/C7PY01006K.
33. A. Lik, L. Fritze, L. Müller, H. Helten,* Catalytic B—C Coupling by Si/B Exchange: A Versatile Route to π-Conjugated Organoborane Molecules, Oligomers, and Polymers, J. Am. Chem. Soc. 2017, 139, 5692—5695 [DOI].
32. H. Helten,* O. Ayhan, T. Lorenz, Bor und Stickstoff statt Kohlenstoff, Nachr. Chem. 2017, 65, 535—541 [DOI].
31. T. Lorenz, M. Crumbach, T. Eckert, A. Lik, H. Helten,* Poly(p-phenylene iminoborane): A Boron—Nitrogen Analog of Poly(p-phenylene vinylene), Angew. Chem. Int. Ed. 2017, 56, 2780—2784 [DOI]; Angew. Chem. 2017, 129, 2824—2828 [DOI] ("Hot Paper").

Highlighted in: "Iminoborane units add inorganic flavor to polymers", S. K. Ritter, Chem. Eng. News 2017, 95(8), 11 [DOI].

30. H. Helten,* Conjugated Inorganic—Organic Hybrid Polymers, Encyclopedia of Inorganic and Bioinorganic Chemistry, 2017, 1—27 [DOI].
29. O. Ayhan, T. Eckert, F. A. Plamper, H. Helten,* Poly(iminoborane)s: An Elusive Class of Main Group Polymers?, Angew. Chem. Int. Ed. 2016, 55, 13321—13325 [DOI]; Angew. Chem. 2016, 128, 13515—13519 [DOI].
28. T. Lorenz, A. Lik, F. A. Plamper, H. Helten,* Dehydrocoupling and Silazane Cleavage Routes to Organic—Inorganic Hybrid Polymers with NBN Units in the Main Chain, Angew. Chem. Int. Ed. 2016, 55, 7236—7241 [DOI]; Angew. Chem. 2016, 128, 7352—7357 [DOI].

Highlighted in: "A New Route to Polymers with NBN Backbone", T. M. Swager, Q. Zhang, Synfacts 2016, 12, 0691 [DOI].

Highlighted in: "Trendbericht Makromolekulare Chemie 2016", M. Sommer, F. Wurm, Nachr. Chem. 2017, 65, 348—358 [DOI].

27. H. Helten,* B=N Units as Part of Extended π-Conjugated Oligomers and Polymers, Chem. Eur. J. 2016, 22, 12972—12982 [DOI].
26. A. P. M. Robertson, E. M. Leitao, T. Jurca, M. F. Haddow, H. Helten,* G. C. Lloyd-Jones,* I. Manners,* Mechanisms of the Thermal and Catalytic Redistributions, Oligomerizations, and Polymerizations of Linear Diborazanes, J. Am. Chem. Soc. 2013, 135, 12670—12683. [DOI]
25. H. Helten, B. Dutta, J. R. Vance, M. E. Sloan, M. F. Haddow, S. Sproules, D. Collison, G. R. Whittell, G. C. Lloyd-Jones, I. Manners, Paramagnetic Titanium(III) and Zirconium(III) Metallocene Complexes as Precatalysts for the Dehydrocoupling/Dehydrogenation of Amine—Boranes, Angew. Chem. Int. Ed. 2013, 52, 437—440; Angew. Chem. 2013, 125, 455—458 ("Very Important Paper").
24. E. M. Leitao, N. E. Stubbs, A. P. M. Robertson, H. Helten, R. J. Cox, G. C. Lloyd-Jones, I. Manners, Mechanism of Metal-Free Hydrogen Transfer between Amine—Boranes and Aminoboranes, J. Am. Chem. Soc. 2012, 134, 16805—16816.
23. V. Blackstone, S. Pfirrmann, H. Helten, A. Staubitz, A. Presa Soto, G. R. Whittell, I. Manners, A Cooperative Role for the Counteranion in the PCl5-Initiated Living, Cationic Chain Growth Polycondensation of the Phosphoranimine Cl3P=NSiMe3, J. Am. Chem. Soc. 2012, 134, 15293—15296.
22. H. Helten, A. P. M. Robertson, A. Staubitz, J. R. Vance, M. F. Haddow, I. Manners, “Spontaneous” Ambient Temperature Dehydrocoupling of Aromatic Amine—Boranes, Chem. Eur. J. 2012, 18, 4665—4680.
21. J. Marinas Pérez, H. Helten, G. Schnakenburg, R. Streubel, A Novel Approach to 1,3,4-Dioxaphospholane Complexes: Acid-Induced Ring Expansion of an Oxaphosphirane Complex. The Problem of Construction and Deconstruction of O,P-Heterocycles, Chem. Asian J. 2011, 6, 1539—1545.
20. H. Helten, G. Schnakenburg, J. Daniels, A. J. Arduengo, III, R. Streubel, When Sterics Overcome Electronics: An Unusual Haptotropic P→N Pentacarbonyltungsten Shift, Organometallics 2011, 30, 84—91.
19. H. Helten, G. Schnakenburg, R. Streubel, Click Reactions of 2H-Azaphosphirene Chromium and Molybdenum Complexes and a Surprisingly Facile Access to a 2H-1,4,2-Diazaphosphole Derivative, Polyhedron 2011, 30, 1799—1805.
18. J. Marinas Pérez, H. Helten, B. Donnadieu, C. A. Reed, R. Streubel, Protonation-Induced Rearrangement of an Oxaphosphirane Complex, Angew. Chem. Int. Ed. 2010, 49, 2615—2618; Angew. Chem. 2010, 122, 2670—2674.
17. J. Marinas Pérez, C. Albrecht, H. Helten, G. Schnakenburg, R. Streubel, Competing ring cleavage of transient O-protonated oxaphosphirane complexes: 1,3-oxaphospholane and η2-Wittig ylide complex formation, Chem. Commun. 2010, 46, 7244—7246.
16. R. Streubel, J. Marinas Pérez, H. Helten, J. Daniels, M. Nieger, Developing click reactions of a 3-ferrocenyl-2H-azaphosphirene complex, Dalton Trans. 2010, 39, 11445—11450.
15. S. Fankel, H. Helten, G. von Frantzius, G. Schnakenburg, J. Daniels, V. Chu, C. Müller, R. Streubel, Novel access to azaphosphiridine complexes and first applications using Brønsted acid-induced ring expansion reactions, Dalton Trans. 2010, 39, 3472—3481.
14. H. Helten, M. Beckmann, G. Schnakenburg, R. Streubel, Synthesis and Reactivity of an Unusual Ferrocenophane Bis(carbene complex), Eur. J. Inorg. Chem. 2010, 2337—2341.
13. H. Helten, J. Daniels, M. Nieger, R. Streubel, Extended π conjugation in 2H-1,4,2-diazaphosphole complexes, New J. Chem. 2010, 34, 1593—1602.
12. H. Helten, M. Engeser, D. Gudat, R. Schilling, G. Schnakenburg, M. Nieger, R. Streubel, Protonation of 2H-Azaphosphirene Complexes: P—N Bond Activation and Ring-Expansion Reactions, Chem. Eur. J. 2009, 15, 2602—2616.
11. H. Helten, J. Marinas Pérez, J. Daniels, R. Streubel, First Brønsted Acid-Induced Ring Expansion of an Oxaphosphirane Complex: A Combined Experimental and DFT Study, Organometallics 2009, 28, 1221—1226.
10. H. Helten, S. Fankel, O. Feier-Iova, M. Nieger, A. Espinosa Ferao, R. Streubel, Strong Evidence for an Unprecedented Borderline Case of Dissociation and Cycloaddition in Open-Shell 1,3-Dipole Chemistry: Transient Nitrilium Phosphane-Ylide Complex Radical Cations, Eur. J. Inorg. Chem. 2009, 3226—3237.
9. H. Helten, G. von Frantzius, G. Schnakenburg, J. Daniels, R. Streubel, How To Tune Acid-Induced Ring Enlargement Reactions — The Strange Case of 2H-Azaphosphirene Complexes and Its Surprising Dichotomy, Eur. J. Inorg. Chem. 2009, 2062—2065.
8. R. Streubel, M. Beckmann, C. Neumann, S. Fankel, H. Helten, O. Feier-Iova, P. G. Jones, M. Nieger, Synthesis, Structure, and Ring-Expansion Reactions of a 3-Ferrocenyl-Substituted 2H-Azaphosphirene Tungsten Complex, Eur. J. Inorg. Chem. 2009, 2090—2095.
7. H. Helten, C. Neumann, A. Espinosa, P. G. Jones, M. Nieger, R. Streubel, Evidence for Ligand-Centered Reactivity of a 17e Radical Cationic 2H-Azaphosphirene Complex, Eur. J. Inorg. Chem. 2007, 4669—4678.
6. R. Vicik, H. Helten, T. Schirmeister, B. Engels, Rational Design of Aziridine-Containing Cysteine Protease Inhibitors with Improved Potency: Studies on Inhibition Mechanism, ChemMedChem 2006, 1, 1021—1028.
5. H. Helten, T. Schirmeister, B. Engels, Theoretical Studies about the Influence of Different Ring Substituents on the Nucleophilic Ring Opening of Three-Membered Heterocycles and Possible Implications for the Mechanisms of Cysteine Protease Inhibitors, J. Org. Chem. 2005, 70, 233—237.
4. H. Helten, T. Schirmeister, B. Engels, Model Calculations about the Influence of Protic Environments on the Alkylation Step of Epoxide, Aziridine, and Thiirane Based Cysteine Protease Inhibitors, J. Phys. Chem. A 2004, 108, 7691—7701.
3. P. W. Musch, C. Remenyi, H. Helten, B. Engels, On the Regioselectivity of the Cyclization of Enyne-Ketenes: A Computational Investigation and Comparison with the Myers-Saito and Schmittel Reaction, J. Am. Chem. Soc. 2002, 124, 1823—1828.
2. B. Walfort, T. Auth, B. Degel, H. Helten, D. Stalke, Copper and Silver Triimidosulfites: S(NtBu)32--Bicapped M3-Triangles Connected via Lithium Halide Ladders or Fragments Thereof, Organometallics 2002, 21, 2208—2214.
1. M. Schmittel, J.-P. Steffen, M. Maywald, B. Engels, H. Helten, P. Musch, Ring size effects in the C2—C6 biradical cyclisation of enyne-allenes and the relevance for neocarzinostatin, J. Chem. Soc., Perkin Trans. 2 2001, 1331—1339.