Organometallics 2011, 30, 1–4 DOI: 10.1021/om1011215
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The Future of Organometallic Chemistry John A. Gladysz Department of Chemistry, Texas A&M University, PO Box 30012, College Station, Texas 77842-3012, United States Received November 29, 2010
This article outlines the advocacy role that a journal can play for the field of organometallic chemistry in an era where agency and foundation programs and initiatives are increasingly directed at “grand challenges”, as opposed to fundamental research in traditional disciplines. It introduces a series of essays and articles on the future of organometallic chemistry, followed by the author’s own views, and highlights some developments from the year 2010 that illustrate the sustained importance of the field. Possible roles for readers and practitioners are discussed.
1. In Support of Our Field
2. The Role of this Issue
This special issue represents the first in a periodic series that will in some manner deal with the future of the title discipline of this journal, organometallic chemistry. It is the aim of the Editors to increasingly involve Organometallics in activities that support its cohorts, and this article deals with both the scientific and political aspects of that mission. Among all public granting agencies and private foundations worldwide, there are none championing the banner of organometallic chemistry per se, at least to the Editors’ knowledge. Rather, priorities and policy focus have tended toward “big science” themes or “grand challenges” such as energy, materials, green processes, and the like. As such, some traditional subdisciplines, such as organometallic chemistry, have the potential to be “lost in the shuffle”. They remain core subjects in the pursuit of many “grand challenges”, all of which require a firm foundation of fundamental knowledge and principles. However, they have ceded ground in the hype, the new journal launches, the new funding initiatives, the increasing proliferation of specialized centers, etc. Nonetheless, practitioners such as the readers of this journal are as committed and enthusiastic as ever regarding their discipline, its relevance, and the broad and vital role that it plays across a wide spectrum of science. Thus, it seems appropriate at this juncture in the history of chemistry for journals such as Organometallics to take up advocacy roles for the subdisciplines they represent, apart from their traditional peer review functions. There are few, if any, policy leaders in science or chemistry who are banging the drums for organometallic chemistry. The Editors would like to see this journal help to address this void. Note that this issue provides a citable source regarding the ongoing relevance of organometallic chemistry, and areas where major developments can be anticipated in the near future. Thus, it may have use in grant proposals, white papers, and similar initiatives. The most recent antecedent that the Editors are aware of was published in 1987.1
The future of a given discipline belongs to its practitioners as a whole. Their aggregate individual and collaborative contributions will define the course of events. In the same sense, discussion and debate regarding long-term trends is not the province of a few gurus, but a matter in which the entire community can engage. Toward this end, this issue features nine perspectives on the future of organometallic chemistry, authored by chemists from a range of career stages, having a variety of research interests, and representing 7þ countries (corresponding authors: Canada, 2; US, 2; Czech Republic, 1; France, 1; Japan, 1; Russia, 1; United Kingdom, 1; additional authors from Spain and The Netherlands). They deserve our thanks for taking the time to share their thoughts and visions. Organometallic chemistry needs voices, and similar efforts from all stakeholders in appropriate forums. The themes of their articles can be grouped as follows. The first raises the question as to whether the future of organometallic chemistry can truly be predicted (Beletskaya and Ananikov), whereas the second presents a broad and visionary synopsis of challenges and opportunities (Higgins, Nichols, Martin, Cea, van der Zant, Richter, and Low). A subsequent set focuses on subjects intimately connected to current “grand challenges”, namely organometallic approaches to water splitting (Piers) and organometallics in green and energy chemistry (Crabtree). This is followed by a treatment of bioorganometallics and drug discovery, analytics, and catalysis (Hillard and Jaouen). Two articles intimately coupled to two classes of instrumentation follow. The first involves the future of organometallic electrochemistry (Geiger), and the second deals with insights into organometallic chemistry in solution from gasphase experiments (Agrawal and Schr€ oder). A subsequent article analyzes opportunities, needs, and future roles for high-throughput experimentation in homogeneous catalysis, and how these may be used to identify new targets and leads in organometallic chemistry (Monfette, Blacquiere, and Fogg). The final contribution applies a crystal ball to
(1) Parshall, G. W. Organometallics 1987, 6, 687. r 2011 American Chemical Society
Published on Web 01/04/2011
pubs.acs.org/Organometallics
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Figure 1. A small fraction of current research in organometallic chemistry highlighted in Chemical and Engineering News during 2010.
photochromic organometallics and approaches to smart chemical systems (Akita).
3. Additional Indicators of Sustained Importance Despite the lack of champions for organometallic chemistry among agencies or foundations (vide supra), there is every indication that the “golden age” of organometallics continues. Justifiably, much has been and will be made in our circles regarding the three Nobel prizes that have been shared by nine individuals for the development of metal-catalyzed organic transformations during the 10 year period 2001-2010.2 But critics, especially those with a “what have you done for me today?” mentality, may counter that some of these stem from developments or discoveries that took place some time ago. In search of an undeniably current metric, I skimmed a few months of the year 2010 issues of Chemical and Engineering News, with an eye toward reportage and highlights from the organometallic world. After rapidly reaching 10 hits, I stopped. Had I thoroughly examined all issues for the entire year, there would easily have been 60þ hits. In the interest of disclosure, these are symbolized in the collage in Figure 1. (2) Gladysz, J. A.; Bochmann, M.; Lichtenberger, D. L.; Liebeskind, L. S.; Marks, T. J.; Sweigart, D. A. Organometallics 2010, 29, 5737.
In brief, the graphical elements represent (1) a palladium(III) dimethyl complex that undergoes reductive elimination of ethane upon irradiation,3 (2) an Fe4S4 active site for the reductive dehydoxylation of an isoprenoid allylic alcohol in pathogenic microorganisms, including a mechanism believed to involve an olefin π complex,4 (3) the palladium-catalyzed trifluoromethylation of aryl halides,5 (4) kilogram-scale palladium-catalyzed oxidations of alcohols,6 (5) the first silicon analogue of a transition-metal alkylidyne complex,7 (6) new mechanistic insights regarding insertions of alkenes into palladium-nitrogen bonds, a key step in olefin hydroaminations,8 (3) (a) Kemsley, J. N. Chem. Eng. News 2010, 88 (24 May), 9. (b) Khusnutdinova, J. R.; Rath, N. P.; Mirica, L. M. J. Am. Chem. Soc. 2010, 132, 7303. (4) (a) Borman, S. A. Chem. Eng. News 2010, 88 (07 June), 39. (b) Wang, W.; Li, J.; Wang, K.; Huang, C.; Zhang, Y.; Oldfield, E. Proc. Natl. Acad. Sci. U.S.A. 2010, 107, 11189. (5) (a) Drahl, C. W. Chem. Eng. News 2010, 88 (28 June), 38. (b) Cho, E. J.; Senecal, T. D.; Kinzel, T.; Zhang, Y.; Watson, D. A.; Buchwald, S. L. Science 2010, 328, 1679. (6) (a) Ritter, S. K. Chem. Eng. News 2010, 88 (05 July), 32. (b) Ye, X.; Johnson, M. D.; Diao, T.; Yates, M. H.; Stahl, S. S. Green Chem. 2010, 12, 1180. (7) (a) Ritter, S. K. Chem. Eng. News 2010, 88 (10 May), 37. (b) Fillippou, A. C.; Chernov, O.; Stumpf, K. W.; Schnakenburg, G. Angew. Chem., Int. Ed. 2010, 49, 3296; Angew. Chem. 2010, 122, 3368. (8) (a) Ritter, S. K. Chem. Eng. News 2010, 88 (07 June), 41. (b) Neukom, J. D.; Perch, N. S.; Wolfe, J. P. J. Am. Chem. Soc. 2010, 132, 6276. (c) Hanley, P. S.; Markovic, D.; Hartwig, J. F. J. Am. Chem. Soc. 2010, 132, 6302.
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(7) the dramatic influence that transition-metal impurities in gold can have on catalysis,9 (8) the key roles played by several metal-catalyzed steps in two enantioselective syntheses of the complex natural product complandadine A,10 (9) a new family of polymetallic wires based upon sp carbon chains that sport redox-active caps, 11 and (10) a stereospecific synthesis of skipped polyynes from vinylcyclopropanes and alkynes mediated by a low-valent titanium reagent.12 The broad scope, high impact, and in several cases paradigm-breaking nature of these reports is obvious. Other news coverage was associated with the symposium held in honor of the Founding Editor of this journal, Prof. Dietmar Seyferth, at the fall 2010 ACS Meeting in Boston.13,14 Importantly, Prof. Seyferth promoted a very liberal definition of organometallic chemistry, as reflected in the scope statement for this journal.15 This constitutes another tactical advantage for the future, and also excuses the likely absence of any transition-metal-or main-group-metal-carbon bond in one of the systems represented in Figure 1.
4. Future Directions My own vision for the future of organometallic chemistry includes the following, which is slanted to complement the themes highlighted in the accompanying articles. First, there will be a continuing emphasis on synthesis. Those who can create novel new forms of matter;graphene and MOFs being two recent examples;will drive much of the destiny of science. One direction will involve targeted syntheses of complex functional organometallic molecules. Organometallic synthesis is finally approaching a level of sophistication that characterized organic synthesis decades ago;namely, there is a growing vocabulary of reactions that can be carried out in metal coordination spheres, for which the range of “functional group tolerance” with respect to the ligands and metal has been established. Another direction for synthesis will involve the stabilization of otherwise very reactive functionalities through steric bulk or shielding. Fine-tuning the steric bulk may allow the observation of new modes of reactivity. The recent investigations of “frustrated Lewis acid/base pairs” that have proved capable of activating diverse types of molecules provide a prime example.16 Catalysis is already a thriving area of organometallic chemistry, and this seems certain to continue, what with the many outstanding challenges involving commodity chemicals (efficient CH4 conversion; selective CO/H2 chemistry), the (9) (a) Drahl, C. W. Chem. Eng. News 2010, 88 (26 July), 41. (b) Lauterbach, T.; Livendahl, M.; Rosell on, A.; Espinet, P.; Echavarren, A. M. Org. Lett. 2010, 12, 3006. (10) (a) Drahl, C. W. Chem. Eng. News 2010, 88 (26 April), 11. (b) Fischer, D. F.; Sarpong, R. J. Am. Chem. Soc. 2010, 132, 5926. (c) Yuan, C.; Chang, C.-T.; Axelrod, A.; Siegel, D. J. Am. Chem. Soc. 2010, 132, 5924. (11) (a) Ritter, S. K. Chem. Eng. News 2010, 88 (31 May), 51. (b) Semenov, S. N.; Taghipourian, S. F.; Blacque, O.; Fox, T.; Venkatesan, K.; Berke, H. J. Am. Chem. Soc. 2010, 132, 7584. (12) (a) Borman, S. A. Chem. Eng. News 2010, 88 (31 May), 51. (b) Macklin, T. K.; Micalizio, G. C. Nature Chem. 2010, 2, 638. (13) Ritter, S. K. Chem. Eng. News 2010, 88 (13 Sept.), 33. (14) Bochmann, M.; Brookhart, M.; Gladysz, J. A.; Lichtenberger, D. L.; Liebeskind, L. S.; Marks, T. J.; Schrock, R. R.; Sweigart, D. A.; Whitmire, K. H. Organometallics 2010, 29, 4647. (15) http://pubs.acs.org/paragonplus/submission/orgnd7/orgnd7_scope. pdf (16) Stephan, D. W.; Erker, G. Angew. Chem., Int. Ed. 2010, 49, 46; Angew. Chem. 2010, 122, 50.
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many unaddressed needs for enantioselective reactions, and the difficultly obtainable goal of an “ideal catalyst”.17 Mechanistic studies will also retain their importance, particularly in response to new reactivity modes and catalyst optimization. Recent times have seen a true revolution in scientific instrumentation, driven in large part by the increasing speed and affordability of computing. There will continue to be abundant opportunities for organometallic chemistry here, ranging from the characterization of isolable compounds, through probing transient reaction intermediates, to the automation of discovery via high-speed robotics. Two of the articles in this issue weigh in on this theme (vide supra). Computational chemistry will also be intimately involved in shaping the future of organometallic chemistry, and input will be solicited from this sector in future forums of this type. In response to the interdisciplinary and multidisciplinary challenges that increasingly drive research, the pairing of organometallic and nonorganometallic chemists will become more and more common. Due in part to such teamwork, organometallic chemistry will accelerate its march into new realms, a trend that several articles in this issue speak to. Some, such as “medicinal organometallic chemistry”, appear to have a particular “hybrid vigor” that is auspicious for future growth.18
5. What You Can Do For starters, readers interested in this topic are encouraged to share their thoughts with the Editors, as there will be future forums for these types of articles. It is critically important for industrial chemists to be represented; their absence constitutes an obvious gap in this issue. For those less interested in serving as authors, “sound bites” or snippets are welcome. Such input can sometimes be incorporated into endeavors in progress. For example, Prof. James P. Collman (Stanford University) commented as given below after being contacted regarding a possible contribution. “...chemists [have] avoided working with paramagnetic compounds, because in most cases, paramagnetism obviates a very useful analytical tool: NMR. Moreover, charged complexes are more difficult to separate using chromatography. I foresee a continuing evolution of hybrid organometallic/ coordination compounds and the exploitation of the unusual catalytic and other reactivity that can be found in certain paramagnetic states. There are already instances of redoxactivated catalysis, which seems to arise from the intermediacy of paramagnetic redox states. Taube showed with mercaptan complexes that π-bonding can be reversed from back to forward via a one-electron increase in the central metal’s oxidation state. Surely a combination of these structural changes and redox properties will lead to the discovery of unusual transformations and catalysts involving these hybrid complexes.”
J. P. Collman, Stanford University Other remarks may be applicable to several branches of chemistry. For example, Prof. Terry Collins (Carnegie-Mellon (17) Gladysz, J. A. Pure Appl. Chem. 2001, 73, 1319. (18) Medicinal Organometallic Chemistry; Jaouen, G., Metzler-Nolte, N., Eds.; Springer: Berlin, 2010; Topics in Organometallic Chemistry 32.
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University) responded as follows. “The chemical enterprise has been built on the premise that seemingly benign chemicals can be commercialized without unacceptable impacts on health or the environment, backed up by the belief that ex post facto control of exposure can adequately compensate for unanticipated toxicities. Both the premise and its safety-net corollary are profoundly wrong. Twentyfirst century chemists will need to understand toxicity and ecotoxicity at a deep enough level to design effectively against endocrine disruption and other forms of developmental toxicity.” Clearly, the organometallic chemical enterprise needs to move toward a sustainable future, and this will be a major driver of research in the decades to come. (19) http://en.wikipedia.org/wiki/Paul_the_Octopus
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Our first follow-up to this issue is likely to be a transcript of a round-table discussion, in which the participants look both forward to the future and back toward recent hits and the predictions made in this series of articles. Indeed, predictions can make for lively theater, and it is hoped that readers will engage. It is a pity that organometallic chemistry does not (yet) have a counterpart to Paul the Octopus, who was able to forecast the outcomes of so many of the soccer matches of the 2010 World Cup so successfully.19 Finally, the most important collective action of organometallic chemists with respect to the future is simply to continue producing outstanding science. In this spirit, the Editors encourage all readers to submit their very best work to Organometallics.
