Abstract
A theoretical study has been carried out at the B3LYP/LANL2DZ level to compare the reactivity of phenyl isocyanate and phenyl isothiocyanate towards titanium(IV) alkoxides. Isocyanates are shown to favour both mono insertion and double insertion reactions. Double insertion in a head-to-tail fashion is shown to be more exothermic than double insertion in a head-to-head fashion. The head-to-head double insertion leads to the metathesis product, a carbodiimide, after the extrusion of carbon dioxide. In the case of phenyl isothiocyanate, calculations favour the formation of only mono insertion products. Formation of a double insertion product is highly unfavourable. Further, these studies indicate that the reverse reaction involving the metathesis of N,N′-diphenyl carbodiimide with carbon dioxide is likely to proceed more efficiently than the metathesis reaction with carbon disulphide. This is in excellent agreement with experimental results as metathesis with carbon disulphide fails to occur. In a second study, multilayer MM/QM calculations are carried out on intermediates generated from reduction of titanium(IV) alkoxides to investigate the effect of alkoxy bridging on the reactivity of multinuclear Ti species. Bimolecular coupling of imines initiated by Ti(III) species leads to a mixture of diastereomers and not diastereoselective coupling of the imine. However if the reaction is carried out by a trimeric biradical species, diastereoselective coupling of the imine is predicted. The presence of alkoxy bridges greatly favours the formation of the d,l (±) isomer, whereas the intermediate without alkoxy bridges favours the more stable meso isomer. As a bridged trimeric species, stabilized by bridging alkoxy groups, correctly explains the diastereoselective reaction, it is the most likely intermediate in the reaction.
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(a) Carter E A and Rossky E J 2006 Acc. Chem. Res. 39 71; (b) Lin Z 2010 Acc. Chem. Res. 43 602; (c) Schröder D, Shaik S and Schwarz H 2000 Acc. Chem. Res. 33 139; (d) Scuseria G E 1999 J. Phys. Chem. A 103 4782; (e) Maseras F and Morokuma K 1995 J. Comput. Chem. 16 1170; (f) Svensson M, Humbel S, Froese R D J, Matsubara T, Sieber S and Morokuma K 1996 J. Phys. Chem. 100 19357; (g) Dapprich S, Komaromi I, Byun K S, Morokuma K, Frisch M J 1999 J. Mol. Struct.: THEOCHEM 461–462 1
(a) Davidson E R 2000 Chem. Rev. 100 351; (b) Bruice T C 2006 Chem. Rev. 106 3119; (c) Balcells D, Clot E and Eisenstein O 2010 Chem. Rev. 110 749; (d) Bifulco G, Dambruoso P, Gomez-Paloma L and Riccio R 2007 Chem. Rev. 107 3744; (e) Proft F D and Geerlings P 2001 Chem. Rev. 101 1451; (f) Kraka E and Cremer D 2010 Acc. Chem. Res. 43 591; (g) Zhao Y and Truhlar D G 2008 Acc. Chem. Res. 41 157
(a) Schwabe T and Grimme S 2008 Acc. Chem. Res. 41 569; (b) Clementi E, Corongiu G, Bahattacharya D, Feuston B, Frye D, Preiskorn A, Rizzo A and Xue W 1991 Chem. Rev. 91 679; (c) Karadakov P B 2001 Annu. Rep. Prog. Chem. Sect. C 97 61
(a) Morokuma K 2007 Bull. Chem. Soc. Jpn. 80 2247; (b) Piyaauksornsak S, Tangthongkul T, Wanbayor R, Wanno B and Ruangpornvisuti V 2009 Struct. Chem. 20 767; (c) Ananikov V P, Musaev D G and Morokuma K 2010 J. Mol. Catal. A: Chem. 324 104
(a) Bo C and Maseras F 2008 Dalton Trans. 2911; (b) Basiuk V A and Basiuk E V 2004 Nanotechnology 2 395
(a) Svelle S, Visur M, Olsbye U, Saepurahman and Bjørgen M 2011 Top Catal. 54 897; (b) North M, Usanov D L and Young C 2008 Chem. Rev. 108 5146; (c) Bakalova S M and Kaneti J 2008 J. Phys. Chem. A 112 13006; (d) Dudding T and Houk K N 2004 Proc. Natl. Acad. Sci. USA 101 5770; (e) Cantillo D, Avalos M, Babiano R, Cintas P, Jimenez J L and Palacios J C 2011 Org. Biomol. Chem. 9 7638; (f) Ishikawa A, Nakao Y, Sato H and Sakaki S 2010 Dalton Trans. 3279; (g) Cowley R E, Eckert N A, Vaddadi S, Figg T M, Cundari T R and Holland P L 2011 J. Am. Chem. Soc. 133 9796; (h) Wang C-M, Wang Y-D, Liu H-X, Xie Z-K and Liu Z-P 2010 J. Catal. 271 386
(a) Pavan Kumar P N V and Jemmis E D 1988 J. Am. Chem. Soc. 110 125; (b) Jemmis E D and Giju K T 1997 Angew. Chem. Int. Ed. Engl. 36 606
(a) Jemmis E D and Giju K T 1998 J. Am. Chem. Soc. 120 6952; (b) Jemmis E D, Phukan A K and Giju K T 2002 Organometallics 21 2254
Kaleta K, Ruhmann M, Theilmann O, Beweries T, Roy S, Arndt P, Villinger A, Jemmis E D, Schulz A and Rosenthal U 2011 J. Am. Chem. Soc. 133 5463
(a) Schofield A D, Nova A, Selby J D, Schwarz A D, Clot E and Mountford P 2011 Chem. Eur. J. 17 265; (b) Tiong P J, Nova A, Groom L R, Schwarz A D, Selby J D, Schofield A D, Clot E and Mountford P 2011 Organometallics 30 1182–1201; (c) Schofield A D, Nova A, Selby J D, Manley C D, Schwarz A D, Clot E and Mountford P 2010 J. Am. Chem. Soc. 132 10484; (d) Tiong P-J, Schofield A D, Selby J D, Nova A, Clot E and Mountford P 2010 Chem. Commun. 46 85; (e) Selby J D, Schulten C, Schwarz A D, Stasch A, Clot E, Jones C and Mountford P 2008 Chem. Commun. 5101
(a) Guiducci A E, Boyd C L, Clot E and Mountford P 2009 Dalton Trans. 5960; (b) Bolton P D, Feliz M, Cowley A R, Clot E and Mountford P 2008 Organometallics 27 6096
(a) Ghosh R, Nethaji M and Samuelson A G 2005 J. Organomet. Chem. 690 1282; (b) Ghosh R and Samuelson A G 2005 Chem. Commun. 115 2017; (c) Ghosh R, Nethaji M and Samuelson A G 2003 Chem. Commun. 113 2556; (d) Kumar A, De S, Samuelson A G and Jemmis E D 2008 Organometallics 27 955; (e) Kumar A and Samuelson A G 2010 J. Organomet. Chem. 695 338; (f) Kumar A and Samuelson A G 2011 J. Chem. Sci. 123 29; (g) Ghosh R 2004 Ph. D Thesis Indian Institute of Science; (h) Kumar A 2009 Ph. D Thesis, Indian Institute of Science
(a) Qin S, Hu C, Yang H and Su Z 2008 J. Org. Chem. 73 4840; (b) Martínez S, Ramos J, Cruz V L and Martínez-Salazar J 2006 Polymer 47 883; (c) Kumar A and Samuelson A G 2010 Chem. Asian J. 5 1830; (d) Kumar A and Samuelson A G 2011 Eur. J. Org. Chem. 951
(a) Becke A D 1993 J. Chem. Phys. 98 5648; (b) Becke A D 1988 Phys. Rev. A 38 3098; (c) Lee C, Yang W and Parr R G 1988 Phys. Rev. B 37 785
(a) Hay P J and Wadt W R 1985 J. Chem. Phys. 82 270; (b) Wadt W R and Hay P J 1985 J. Chem. Phys. 82 284; (c) Hay P J and Wadt W R 1985 J. Chem. Phys. 82 299
Gaussian 03, Revision C.02, Frisch M J, Trucks G W, Schlegel H B, Scuseria G E, Robb M A, Cheeseman J R, Montgomery Jr. J A, Vreven T, Kudin K N, Burant J C, Millam J M, Iyengar S S, Tomasi J, Barone V, Mennucci B, Cossi M, Scalmani G, Rega N, Petersson G A, Nakatsuji H, Hada M, Ehara M, Toyota K, Fukuda R, Hasegawa J, Ishida M, Nakajima T, Honda Y, Kitao O, Nakai H, Klene M, Li X, Knox J E, Hratchian H P, Cross J B, Bakken V, Adamo C, Jaramillo J, Gomperts R, Stratmann R E, Yazyev O, Austin A J, Cammi R, Pomelli C, Ochterski J W, Ayala P Y, Morokuma K, Voth G A, Salvador P, Dannenberg J J, Zakrzewski V G, Dapprich S, Daniels A D, Strain M C, Farkas O, Malick D K, Rabuck A D, Raghavachari K, Foresman J B, Ortiz J V, Cui Q, Baboul A G, Clifford S, Cioslowski J, Stefanov B B, Liu G, Liashenko A, Piskorz P, Komaromi I, Martin R L, Fox D J, Keith T, Al Laham M A, Peng C Y, Nanayakkara A, Challacombe M, Gill P M W, Johnson B, Chen W, Wong M W, Gonzalez C and Pople J A 2004 Wallingford CT: Gaussian, Inc
Frisch M J, Trucks G W, Schlegel H B, Scuseria G E, Robb M A, Cheeseman J R, Scalmani G, Barone V, Mennucci B, Petersson G A, Nakatsuji H, Caricato M, Li X, Hratchian H P, Izmaylov A F, Bloino J Zheng G, Sonnenberg J L, Hada M, Ehara M, Toyota K, Fukuda R, Hasegawa J, Ishida M, Nakajima T, Honda Y, Kitao O, Nakai H, Vreven T, Montgomery J A, Peralta Jr, J E, Ogliaro F, Bearpark M, Heyd J J, Brothers E, Kudin K N, Staroverov V N, Kobayashi R, Normand J, Raghavachari K, Rendell A, Burant J C, Iyengar S S, Tomasi J, Cossi M, Rega N, Millam J M, Klene M, Knox J E, Cross J B, Bakken V, Adamo C, Jaramillo J, Gomperts R, Stratmann R E, Yazyev O, Austin A J, Cammi R, Pomelli C, Ochterski J W, Martin R L, Morokuma K, Zakrzewski V G, Voth G A, Salvador P, Dannenberg J J, Dapprich S, Daniels A D, Farkas O, Foresman J B, Ortiz J V, Cioslowski J and Fox D J 2009 Gaussian 09, Revision A.02, Wallingford CT: Gaussian, Inc
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AGS thanks the Department of Science and Technology (DST), New Delhi for the award of a research grant and AK gratefully acknowledges for Post Doctoral Fellowship from Indian Institute of Science (IISc), Bangalore. Authors also thank Prof. ED Jemmis, Dr. S De and Dr. S Dinda and M Thenraj for their help and suggestions. Thanks are also due to Supercomputer Education and Research Centre (SERC) of IISc for computational facilities.
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KUMAR, A., SAMUELSON, A.G. Computational tools for mechanistic discrimination in the reductive and metathesis coupling reactions mediated by titanium(IV) isopropoxide. J Chem Sci 124, 1343–1352 (2012). https://doi.org/10.1007/s12039-012-0333-2
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DOI: https://doi.org/10.1007/s12039-012-0333-2