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ADDENDUM to MOLECULAR MECHANICS PROBLEM SET Fall Semester, 2005

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ADDENDUM to MOLECULAR MECHANICS PROBLEM SET Fall Semester, 2005 ADDENDUM TO MOLECULAR MECHANICS PROBLEM SET Fall semester, 2005 A number of recent journal articles and review articles contain information that is relevant to a significant number of examples in the problem set. If you choose one of the following problems for your MMX project, you should be sure to consult the appropriate review article(s) (as well as the cited references where the problem is first presented). There are three relevant review articles from the series "Advances in Strain in Organic Chemistry"; Halton, B., Ed.; JAI: London (available in the library): for anti Bredt compounds and small-ring propellanes (Nos. 1, 13, others?): Szeimies, G.; 1992, Vol 2, p 1 for cyclophanes (Nos. 3, 27, 34, 52, 53, 56-58, 63, 119, 125, 181, 187, 189, 193, 197, 220, others?): Bickelhaupt, F.; de Wolf, W. H.; 1993, Vol 3, p 185 for fenestranes (Nos. 66-70, 161, others?): Luef, W.; Keese, R.; 1993, Vol 3, p 229 Dodziuk, H. Top. Stereochem. 1994, 21, 351: this is a review article on inverted or pyramidalized sp3- hybridized carbons in strained compounds (Nos. 78, 149, 352, others?) A very recent paper from this same research group elaborates on several of the compounds calculated in 352 and suggests a new structure with only one inverted carbon: Dodziuk, H.; Dolgones, G.; Leszcynski, J. Tetrahedron 2003, 59, 10013. Kane, V. V.; De Wolf, W. H.; Bickelhaupt, F. Tetrahedron 1994, 50, 4575: this is another review article on the topic of cyclophanes (see earlier). An even more recent review article on the synthesis and reactivity of strained cyclophanes is by Bickelhaupt, F.; de Wolf, W. H. J. Phys. Org. Chem. 1998, 11, 362. Beckhaus, H.-D.; Rüchardt, C.; Lagerwall, D. R.; Paquette, L. A.; Wahl, F.; Prinzbach, H. J. Am. Chem. Soc. 1994, 116, 11775 for experimental data on the heats of formation and strain energies of the C20H20 symmetrical compounds pagodane and dodecahedrane (and their derivatives) for Problems 72, 77, 78, 83, 146, 147, 172, 186, and others. For additional work on unsaturated compounds and bridged compounds related to pagodane and dodecahedrane in Problems 113, 285, see Pinkos, R.; Weiler, A.; Voss, T.; Weber, K.; Wahl, F.; Melder, J.-P.; Fritz, H.; Hunkler, D.; Prinzbach, H. Liebigs Ann. Chem. 1997, 2069. For a recent summary of all of the MMX calculations on the pagodanes (and their various enes, dienes, trienes, etc.) see Wollenweber, M.; Etzkorn, M.; Reinbold, J.; Wahl, F.; Voss, T.; Melder, J.-P.; Grund, C.; Pinkos, R.; Hunkler, D.; Keller, M.; Wörth, J.; Knothe, L.; Prinzbach, H. Eur. J. Org. Chem. 2000, 3855, especially Tables 7-10; Reinbold, J.; Bertau, M.; Voss, T.; Hunkler, D.; Knothe, L.; Prinzbach, H.; Neschchadin, D.; Gescheidt, G.; Mayer, B.; Martin, H.-D.; Heinze, J.; Prakash, G. K. S.; Olah, G. A. Helv. Chim. Acta 2001, 84, 1518. Müller, P.; Mareda, J.; Milin, D. J. Phys. Org. Chem. 1995, 8, 507: this article gives many additional data points related to the solvolysis of bridgehead substrates, Problem 106B. An even more complete picture is obtained from calculations on gas-phase reactions in a very recent article: Abboud, J-L. M.; Herreros, M.; Notario, R.; Lomas, J. S.; Mareda, J.; Müller, P.; Rossier, J.-C. J. Org. Chem. 1999, 64, 6401. Sygula, A.; Abdourazak, A. H.; Rabideau, P. W. J. Am. Chem. Soc. 1996, 118, 339: this article has calculations and experimental data related to corannulene and related compounds, Problem 231. Marchand, A. P.; Xing, D.; Bott, S. G. Tetrahedron 1996, 52, 825 presents new information about the 2 crowded molecules (Z)- and (E)-1,2-di(1-adamantyl)ethene; cf Problem 198. Qiao, X.; Padula, M. A.; Ho, D. M.; Vogelaar, N. J.; Schutt, C. E.; Pascal, R. A., Jr. J. Am. Chem. Soc. 1996, 118, 741 has additional calculated and experimental data on the twisted aromatic compounds found in Problem 64. Then, for some spectacular examples of a twisted polycyclic aromatic compound see the following: Qiao, X.; Ho, D. M.; Pascal, R. A., Jr. Angew. Chem., Int. Ed. Engl. 1997, 36, 1531; Tong, L.; Lau, H.; Ho, D. M.; Pascal, R. A., Jr. J. Am. Chem. Soc. 1998, 120, 6000.] Boese, R.; Haumann, T.; Jemmis, E. D.; Kiran, B.; Kozhushkov, S.; de Meijere, A. Liebigs Ann. Chem. 1996, 913 presents calculations and X-ray crystal structures for the triangulanes of Problem 248; some even more spectacular triangulanes have been synthesized by this same research group: Seebach, M. von; Kozhushkov, S. I.; Boese, R.; Benet-Bucholz, J.; Yufit, D. S.; Howard, J. A. K.; de Meijere, A. Angew. Chem., Int. Ed. Engl. 2000, 39, 2495. Alder, R. W.; East, S. P. Chem. Rev. 1996, 96, 2097 presents an extensive review of the experimental and computational details on bicyclo [m.n.o] compounds in which the bridgehead substituents are either both outside the ring (the normal situation) or one inside/one outside or both inside. This will be relevant to Problems 14 and 35 (both of which are mentioned in this review) and to other problems that you might devise on your own. Especially interesting are the MM2 calculated data in Table 1. Gwaltney, S. L.; Sakata, S. T.; Shea, K. J. J. Org. Chem. 1996, 61, 7438 is the full paper of the 1992 communication that was the basis for Problem 142. Sakamoto, Y.; Miyoshi, N.; Hirakida, M.; Kusumoto, S.; Kawase, H.; Rudzinski, J. M.; Shinmyozy, T. J. Am. Chem. Soc. 1996, 118, 12267 is the full paper related to the communication that served as the basis for Problem 257; for work on the mechanism by which this ?pinwheel” molecule inverts, see Hori, K.; Sentou, W.; Shinmyozu, T. Tetrahedron Lett. 1997, 52, 8955. See, also, the recent calculations on these compounds, reported by Bettinger, H. F.; Schleyer, P. von R.; Schaefer, H. F., III J. Am. Chem. Soc. 1998, 120, 1074. Li, W.; Fox, M. A. J. Am. Chem. Soc. 1996, 118, 11752 presents data on dimers, trimers, tetramers, etc. from substituted cyclobutadienes; these "ladder" compounds are related to those in Problem 164. (See, also, Hopf's 2003 article on "ladderanes" that is mentioned on p. 4 of this addendum.) Göttlich, R.; Kahrs, B. C.; Krüger, J.; Hoffmann, R. W. J. Chem. Soc., Chem. Commun. 1997, 247 has additional examples and insights related to Problems 265, 275, 276 and 347. See, also, Stahl, M.; Schopfer, U.; Frenking, G,; Hoffmann, R. W. J. Org. Chem. 1997, 62, 3702; Stahl, M.; Schopfer, U. J. Chem. Soc., Perkin Trans. 2 1997, 905; Hoffmann, R. W.; Schopfer, U.; Stahl, M. Tetrahedron Lett. 1997, 38, 4055; Götlich, R.; Schopfer, U.; Stahl, M.; Hoffmann, R. W. Liebigs Ann. Chem. 1997, 1757;Schopfer, U.; Stahl, M.; Brandl, T.; Hoffmann, R. W. Angew. Chem., Int. Ed. Engl. 1997, 36, 1745; Hoffmann, R. W.; Göttlich, R. Liebigs Ann. Chem. 1997, 2103. For an outstanding review on these restricted conformation molecules (and interesting extensions of them), see Hoffmann, R. W.; Stahl, M.; Schopfer, U.; Frenking, G. Chem. Eur. J. 1998, 4, 559. For even more recent data on these "flexible molecules with defined shape" see Hoffmann, R. W.; Stenkamp, D.; Trieselmann, T.; Göttlich, R. Eur. J. Org. Chem. 1999, 2915; Stenkamp, D.; Hoffmann, R. W.; Göttlich, R. Eur. J. Org. Chem. 1999, 2929. Another comprehensive review is Hoffmann, R. W. Angew. Chem., Int. Ed. Engl. 2000, 39, 2055. An interesting recent extension of these ideas is found "neighboring dimethylpentane segments": Hoffmann, R. W.; Göttlich, R.; Schopfer, U. Eur. J. Org. Chem. 2001, 1865. And for the very latest word, see the article about the conformational analysis of meso-2,3,4,5-tetramethylhexane and meso-2,3,4,5,6,7-hexamethyloctane: Hoffmann, R. W.; Menzel, K. Eur. J. Org. Chem. 2001, 2749. Kuck, D. Liebigs Ann. Chem. 1997, 1043 has an updated discussion on centrosymmetric compounds (Problem 255); Kuck, D.; Krause, R. A.; Gestmann, D.; Posteher, F.; Schuster, A. Tetrahedron 1998, 3 54, 5247. For a recent survey of compounds containing planar (or nearly planar) tetravalent carbons (Problems 65- 70, 161, 273), see Röttger, D.; Erker,. G. Angew. Chem., Int. Ed. Engl. 1997, 36, 812. For recent work on the conformations of 1,4,7-cyclononatriyne (Problem 9 and others?) see Yavari, I.; Taherpour, A.; Jabbari, A. J. Chem. Res. (S) 1997, 210. For further experimental and theoretical work on the strained Diels-Alder adducts of Problem 271, see Sauer, J.; Breu, J.; Herges, R. Neumann, H.; Kammermeier, S. Liebigs Ann. Chem. 1997, 1473.; Kammermeier, S.; Jones, P. G.; Herges, R. Angew. Chem., Int. Ed. Engl. 1997, 36, 1757. For further experimental work on the partial and complete hydrogenation of [2,2]-p-cyclophane (related to Problems 280 and 295), see Hopf, H.; Savinsky, R.; Jones, P. G.; Dix, I.; Ahrens, B. Liebigs Ann. Chem. 1997, 1499. The full paper (calculations and experimental results) on the 10-membered ring diaza diynes in Problem 245 is Ritter, J.; Gleiter, R.; Irngartinger, H.; Oeser, T. J. Am. Chem. Soc. 1997, 119, 10599. For further work on bridgehead allylic cations that are incapable of resonance stabilization (see Problems 90 and 112), there is a recent paper by Tokunaga, K.; Ohtsu, T.; Ohga, Y.; Takeuchi, K. J. Org. Chem. 1998, 63, 2209. For a delightful and amusing (!) mini-review on the ?molecular brake” of Problem 214 and the ?molecular ratchet” of Problem 307, see Davis, A. P. Angew. Chem., Int. Ed. Engl. 1998, 37, 909. For extensive new experimental work on these "molecular motors," see Kelly, T. R.; Silva, R. A.; De Silva, H.; Jasmin, S.; Zhao, Y. J. Am. Chem. Soc. 2000, 122, 6935. For an extensive review of both the "molecular brake" of Problem 214 and the "molecular ratchet" of Problem 307, as well as for more recent developments, see Kelly, T.
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