DE2449257C3 - Titanium complex, process for its preparation and hydrogenation process - Google Patents

Description

2. A process for preparing the compound according to claim 1, characterized by reacting Titandicyclopentadienyl-dicarbonyl with diphenylacetylene at O to 50 ⁰ C under immediate removal of the end product

3. Process for the hydrogenation of unsaturated compounds in the presence of catalysts, characterized in that the catalyst used is a compound of the formula

(C ₅ H ₅ ) ₂ Ti (CO) C2 (QH5) 2

used.

25th

From "Bulletin of the Chemical Society of Japan", Volume 39, pages II 78-1182 (1966), it is known some acetylenic and olefinic compounds by using dicarbonyl-dicyclopentadienyltitanium with the formula

Ti (C ₅ H ₅ I ₂ (CO) ₂

to hydrogenate as a catalyst.

However, this catalyst does not prove to be sufficiently effective because high hydrogen pressures (e.g. 50 atmospheres) and relatively high temperatures are required, and in addition it is at the Hydrogenation of many organic compounds ineffective.

It has been found that a catalyst obtained from the reaction product of dicarbonyl-dicyclopentadienyltitanium with diphenylacetylene, has a much higher catalytic effectiveness than that Dicarbonyl-dicyclopentadienyltitanium itself.

The invention therefore relates to a titanium complex of the formula

C, H,

Ti

C ₅ H ₅ CO

C Q, H,

CC ₆ H ₅

and the process for its preparation, which is characterized in that titanium dicyclopentadienyl dicarbonyl is reacted with diphenylacetylene at 0 to 50 ° C. with immediate removal of the end product. The titanium complex is prepared in an inert solvent.

The invention also provides a hydrogenation process for olefinic or acetylenic ones Compounds using the titanium complex according to the invention as a catalyst. The inventive The process is carried out at room temperature and low hydrogen pressures. One works preferably in solution in an inert solvent.

The hydrogenation is preferably carried out in the presence of liquid aliphatic, cycloaliphatic or aromatic hydrocarbons carried out at room temperature

The hydrogen pressure is not a critical factor in the hydrogenation reaction; however, becomes to easier or more expedient to carry out the process at a pressure of 1 to 5 atmospheres absolutely preferably carried out at atmospheric pressure

The hydrogenation reaction according to the invention can be carried out starting from any organic compound which has at least one ethylenic or acetylenic unsaturation and not with the Catalyst reacts

According to the above, the hydrogenation can be carried out on olefins, such as Ethylene, propylene, butenes, pentenes, hexenes, cyclohexenes, heptenes and the like, diolefins such as Butadiene, isoprene, phenylbutadiene, diphenylbutadiene, pentadienes, cyclooctadienes, acetylenic compounds, such as methylacetylene, phenylacetylene, diphenylacetylene.

The following examples serve to illustrate the invention.

example 1
Production of Ph ₂ C ₂ (CO) TiCp ₂

400 cm ^{3 of} heptane were added to a mixture of 4.2 g of TiCp ₂ (CO) ₂ and 6.7 g of Ph ₂ C ₂ in the solid state. The clear and stirred solution (25 ° C. by means of thermostat) was kept continuously under vacuum (slight vacuum from an open water pump); a microcrystalline gold-yellow solid began to separate out after 4 hours. The reaction was ended after 24 hours (final volume 500 cm ³ ). The solid was filtered and washed with heptane. The yield was 3.5 g.

Analysis:

Calc .: C 78.2, H 5.22;
Found: C 78.20, H 5.25.

vCO = 2000 cm- ', vC = C = 1780 cm-' (Nujol).

NMR (C ₆ D ₆ ) multiplet at 2.9 τ (10 H, Ph),
Singlet at 5.0 τ (10 H, ep).

Example 2

53 A solution was prepared from 0.15 g of TiCp ₂ (CO) Ph ₂ C ₂ in 50 cm ^{3 of} heptane, to which 1.5 g

PhCH = CH -CH = CH-Ph

were added (which is sparingly soluble in heptane). Hydrogen was introduced and an absorbs rapidly for 15 minutes while all of the olefin went into solution.

Air was admitted to the catalyst

fto oxidize, resulting in substances insoluble in heptane led. A major product along with traces of dibenzyl was identified by thin layer chromatography identified that had arisen from the catalyst.

The crude product was after evaporation of the

fts heptane recrystallized from heptane to obtain 1.2 g of a product with a melting point of 53-54 ° C (literature: 52-53 ⁰ C), which was identified by NMR analysis.

40

45

Examples 3 to 7

The following examples relate to the hydrogenation of various organic substrates Room temperature and room or atmospheric pressure, carried out according to the previous example became.

table

The table below shows hydrogenation tests with the same organic ones for comparison purposes Substrates listed, with the catalyst according to the invention and titanium dicyclopentadienyl dicarbonyl be used.

The results obtained clearly show that the catalyst according to the invention has a greater activity than the known compound

Catalytic hydrogenation in the presence of Ti (CsHs) 2 (CO) 2 or Ti (CsHs) ₂ (PhC ₂ PhXCO) Conditions: 1 atm. H ₂ ; Room temperature, heptane as solvent (50 cm ³ )

Olefin or acetylenic mmol Ticpj (CO) 2 Ticp2 (PhC2PhXCO) Substrate / Reaction % hydrogenated connection 2.8 Catalysis time 5.5 sator 5.55 Relationship 5.55 nis 6.95 mmol mmol PhC = CPh 6.95 0.77 3.6 3 hours. 30% PhCH ₂ CH ₂ Ph PhC = CPh 18.3 0.39 14.5 1-3 min. 100% PhCH ₂ CH ₂ Ph trans-stilbene 183 0.64 8.7 5h no reaction trans-stilbene not 0.34 163 15 minutes. 100% PhCHjCH ₂ Ph PhCH = CH-CH = CHPh under 0.77 9.0 3 hours. no reaction PhCH = CH-CH = CHPh seeks 0.49 18.0 15 minutes. 100% Ph (CH ₂ J ₄ Ph Cyclohexene 0.60 32.0 24 hours no reaction Cyclohexene 0.39 47.0 14h 90% cycloxene 1-octene n.d. 1-octene > 50.0 5 min. 100% octane Ph = phenyl, ep = cyclopentadienyl.

Claims (1)

Patent claims: 1. Titanium complex of the formula Ti I C ₅ H, CH ₅ CO CC ₆ H ₅