Premium
Transfer Hydrogenation Processes to μ 3 ‐Alkylidyne Groups on the Organotitanium Oxide [Ti 3 Cp $\rm{^{{\ast}}_{3}}$ O 3 ]
Author(s) -
Andrés Román,
Galakhov Mikhail V.,
GómezSal María Pilar,
Martín Avelino,
Mena Miguel,
del Carmen MoralesVarela María,
Santamaría Cristina
Publication year - 2002
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/1521-3765(20020215)8:4<805::aid-chem805>3.0.co;2-h
Subject(s) - oxide , transfer (computing) , chemistry , photochemistry , organic chemistry , computer science , parallel computing
The photochemical treatment of μ 3 ‐alkylidyne complexes [{TiCp*( μ ‐O)} 3 ( μ 3 ‐CR)] (R=H ( 1 ), Me ( 2 ), Cp*= η 5 ‐C 5 Me 5 ) with the amines (2,6‐Me 2 C 6 H 3 )NH 2 , Et 2 NH, and Ph 2 NH and the imine Ph 2 C=NH leads to the partial hydrogenation of the alkylidyne moiety that is supported on the organometallic oxide, [Ti 3 Cp $\rm{^{{\ast}}_{3}}$ O 3 ], and the formation of new oxoderivatives [{TiCp*( μ ‐O)} 3 ( μ ‐CHR)(R′NR″)] (R″=2,6‐Me 2 C 6 H 3 , R′=H, R=H ( 3 ), Me ( 4 ); R′=R″=Et, R=H ( 5 ), Me ( 6 ); R′=R″=Ph, R=H ( 7 ), Me ( 8 )) and [{TiCp*( μ ‐O)} 3 ( μ ‐CHR)(N=CPh 2 )] (R=H ( 9 ), R=Me ( 10 )), respectively. A sequential transfer hydrogenation process occurs when complex 1 is treated with t BuNH 2 , which initially gives the μ ‐methylene [{TiCp*( μ ‐O)} 3 ( μ ‐CH 2 )(HN t Bu)] ( 11 ) complex and finally, the alkyl derivative [{TiCp*( μ ‐O)} 3 ( μ ‐N t Bu)Me] ( 12 ). Furthermore, irradiation of solutions of the μ 3 ‐alkylidyne complexes 1 or 2 in the presence of diamines o ‐C 6 H 4 (NH 2 ) 2 and H 2 NCH 2 CH 2 NH 2 (en) affords [{TiCp*( μ ‐O)} 3 ( μ 3 ‐ η 2 ‐NC 6 H 4 NH)] ( 13 ) and [{TiCp*( μ ‐O)} 3 ( μ 3 ‐ η 2 ‐NC 2 H 4 NH)] ( 14 ) by either methane or ethane elimination, respectively. In the reaction of 1 with en, an intermediate complex [{TiCp*( μ ‐O)} 3 ( μ ‐CH 2 )(NHCH 2 CH 2 NH 2 )] ( 15 ) is detected by 1 H NMR spectroscopy. Thermal treatment of the complexes 4 – 10 quantitatively regenerates the starting μ 3 ‐alkylidyne compounds and the amine R′ 2 NH or the imine Ph 2 C=NH; however, heating of solutions of 3 or 4 in [D 6 ]benzene or a equimolecular mixture of both at 170 °C produces methane, ethane, or both, and the complex [{TiCp*( μ ‐O)} 3 { μ 3 ‐ η 2 ‐NC 6 H 3 (Me)CH 2 }] ( 16 ). The molecular structure of 8 has been established by single‐crystal X‐ray analysis.