Platinum complexes with binaphthyl diphosphine ligands for catalyzing hydroxycarbonylation of olefinically unsaturated compounds

Abstract

Disclosed are platinum complexes with binaphthyl diphosphine ligands for catalyzing hydroxycarbonylation of olefinically unsaturated compounds.

Description

TECHNICAL FIELD

[0001] The present invention relates to platinum complexes with binaphthyl diphosphine ligands for the catalytic hydroxycarbonylation of olefinically unsaturated compounds. BACKGROUND

[0002] Hydroxycarbonylation of olefinically unsaturated compounds is a method of increasing importance. Hydroxycarbonylation is to be understood as meaning the direct reaction of an olefinically unsaturated compound, for example an olefin, with carbon monoxide in the presence of a metal or metal complex and a ligand, to give the corresponding acid:

[0003]

[0004] Scheme 1 : General reaction scheme for the hydroxycarbonylation of olefinically unsaturated compounds

[0005] EP 3388414 A1 describes a process for the hydroformylation of cyclooctadiene (COD) using 4-([1,1 ':3',1 "-terphenyl]-2'-yloxy)-S-dinaphtho[2,1 -d:1 ',2'-f][1,3,2]dioxaphosphepin.

[0006] A disadvantage of palladium is its high price. SUMMARY

[0007] The technical problem addressed by the present invention is to provide new complexes with a metal as central atom which is less expensive than palladium. In addition, the complexes should also achieve good conversion rates in the hydroxycarbonylation.

[0008] This object is achieved by the complex according to the present invention.

[0009] Complex comprising Pt and a compound of formula (I)

[0010] (I)

[0011] wherein

[0012] R 1 , R 2 , R 3 , R 4 are each, independently of one another, selected from -(Ci-C 12 )-alkyl, -(C6-C 20 )-heteroaryl.

[0013] The expression "(Ci-C 12 )-alkyl" includes straight-chain and branched alkyl groups having 1 to 12 carbon atoms. These are preferably (Ci-C8)-alkyl groups, more preferably (Ci-C6)-alkyl groups, most preferably (Ci-C4)-alkyl groups.

[0014] The expression "(C6-C 20 )-heteroaryl" includes monocyclic or polycyclic aromatic hydrocarbon groups having 6 to 20 carbon atoms, wherein one or more of the carbon atoms are replaced by a heteroatom. Preferred heteroatoms are N, O and S. The (C6-C 20 )-heteroaryl groups have 6 to 20, preferably 6 to 14 and more preferably 6 to 10 ring atoms. Thus, for example, within the scope of the present application, pyridyl is a C6-heteroaryl group.

[0015] Suitable (C6-C 20 )-heteroaryl groups having at least 6 ring atoms are, inter alia, pyridyl, pyridazinyl, pyrimidinyl, pyrazinyl, benzofuranyl, indolyl, isoindolyl.

[0016] In one embodiment, at least two of the R 1 , R 2 , R 3 , R 4 groups are -(C6-C 20 )-heteroaryl groups having at least 6 ring atoms.

[0017] In one embodiment, the R 1 and R 3 groups are each -(C6-C 20 )-heteroaryl groups having at least 6 ring atoms.

[0018] In one embodiment, the R 1 and R 3 groups are each 2-pyridyl.

[0019] In one embodiment, R 2 and R 4 are -(C1-C 12 )-alkyl.

[0020] In one embodiment, R 2 and R 4 are tert-butyl.

[0021] In one embodiment, the compound (I) has the structure (1):

[0022] (1).

[0023] The present application further relates to the use of the complex according to the present application for catalysing a hydroxy carbonylation reaction.

[0024] The process comprises the following process steps:

[0025] a) initial charging of an olefinically unsaturated compound;

[0026] b) adding a complex as described above, or a compound of formula (I) and a substance comprising Pt

[0027] (I)

[0028] wherein

[0029] R 1 , R 2 , R 3 , R 4 each, independently of one another, is selected from the group consisting of -(Ci-C 12 )-alkyl, -(C6-C 20 )-heteroaryl;

[0030] c) adding an acid;

[0031] d) inputting CO;

[0032] e) heating the reaction mixture from a) to d), where the olefinically unsaturated compound is converted into a carboxylic acid.

[0033] Here, the process steps a), b), c) and d) can be carried out in any desired order. However, generally, the addition of CO is carried out after the co-reactants have been initially charged in steps a) to c). Furthermore, it is also possible to input the CO in two or more steps, such that, for example, a part of the CO is first inputted, the mixture is then heated and a further part of the CO is then inputted.

[0034] The olefinically unsaturated compound used as a reactant in the process according to the application contains one or more carbon-carbon double bonds. For simplification, these compounds are also referred to as olefins in the following. The double bonds can be terminal or internal.

[0035] In one variant of the process, the olefinically unsaturated compound contains no further functional groups in addition to the carbon-carbon double bond.

[0036] In one variant of the process, the olefinically unsaturated compound is selected from the group consisting of ethylene, propylene, 1 -butene, cis- and / or trans-2-butene, isobutene, 1,3-butadiene, 1 -pentene, cis- and / or trans-2-pentene, 2-methyl-1 -butene, 3-methyl-1 -butene, 2-methyl-2-butene, hexene, tetramethylethylene, heptene, 1 -octene, 2-octene, di-n-butene or mixtures thereof.

[0037] In one variant of the process, the acid in process step c) is selected from the group consisting of acetic acid, perchloric acid, sulfuric acid, phosphoric acid, methylphosphonic acid, methanesulfonic acid, trifluoromethanesulfonic acid, tert-butanesulfonic acid, p-toluenesulfonic acid (PTSA), 2-hydroxypropane-2-sulfonic acid, 2,4,6-trimethylbenzenesulfonic acid, dodecylsulfonic acid, camphorsulfonic acid.

[0038] In one variant of the process, the acid in process step c) is acetic acid (AcOH).

[0039] In one variant of the process, the substance comprising Pt is selected from the group consisting of platinum dichloride (PtCl2), platinum(II) acetylacetonate [Pt(acac)2], platinum(II) acetate [Pt(OAc)2], dichloro(1,5-cyclooctadiene)platinum(II) [Pt(cod)2Cl2], bis(dibenzylideneacetone)platinum [Pt(dba)2], bis(acetonitrile)dichloroplatinum(II) [Pt(CH3CN)2Cl2], (cinnamyl)dichloroplatinum [Pt(cinnamyl)Cl2].

[0040] In one variant of the process, the substance comprising Pt is selected from the group consisting of platinum dichloride (PtCl2), platinum(II) acetylacetonate [Pt(acac)2], platinum(II) acetate [Pt(OAc)2].

[0041] In step d), CO is preferably introduced at a CO partial pressure of between 0.1 and 10 MPa (1 and 100 bar), preferably between 1 and 8 MPa (10 and 80 bar), more preferably between 2 and 6 MPa (20 and 60 bar).

[0042] In step e) of the process according to the application, the reaction mixture is preferably heated to a temperature in the range from 60 to 160°C, preferably in the range from 80 to 140°C, more preferably in the range from 80 to 120°C, thereby converting the olefinically unsaturated compound into an acid. DETAILED DESCRIPTION

[0043] The application will be explained in more detail hereinafter by way of examples.

[0044] Converting 1-octene to acid

[0045]

[0046] Reaction conditions: 1-Octene (1.0 mmol), PtCI2(0.01 mmol, 1.0 mol%), ligand: bidentate phosphine ligand (0.022 mmol, 2.2 mol%), sulfuric acid [0.3 M] 0.5 mL, AcOH (1.5 mL), pressure (CO): 40 bar, temperature: 120 °C, reaction time: 18 hours.

[0047] The reaction was carried out in the process according to the application with ligand (1) and with ligand (2) as a comparative experiment:

[0048] (1)

[0049] (2).

[0050] Here, the process according to the application with ligand (1) provides a yield of 50%. In contrast, in the comparative experiment with ligand (2) only a yield of 26% is achieved.

[0051] The price of Pt is lower than the price of Pd. Thus, the object is achieved by the complex according to the application.

Claims

1. Complex comprising Pt and a compound of formula (I) ###0001### (I) wherein （I） 4. Complex according to claim 1 or 2, wherein the compound (I) has the structure (1): ###0002### R 1 and R 3 each independently of one another are a -(C6-C 20 )-heteroaryl group having at least 6 ring atoms; and R 2 and R 4 each independently of one another is -(Ci-C 12 )-alkyl.

2. The complex according to claim 1, wherein the R 1 and the R 3 groups are each 2-pyridyl.

3. Complex according to claim 1 or 2, wherein R 2 and R 4 are tert-butyl.

5. Process for the conversion of an olefinically unsaturated compound into a carboxylic acid, comprising the following process steps: a) initial charging of the olefinically unsaturated compound; b) addition of a complex according to any of claims 1 to 4, or of a compound of formula (I) and a substance comprising Pt: ###0003### (I) wherein R1 = R2 = R3 = R4 = R5 = R6 = R7 = R8 = R9 = R10 = R11 = R12 = R13 = R14 = R15 = R16 = R17 = R18 = R19 = R20 = R21 = R22 = R23 = R24 = R25 = R26 = R27 = R28 = R29 = R30 = R31 = R32 = R33 = R34 = R35 = R36 = R37 = R38 = R39 = R40 = R41 = R42 = R43 = R44 = R45 = R46 = R47 = R48 = R49 = R50 = R51 = R52 = R53 = R54 = R55 = R56 = R57 = R58 = R59 = R60 = R61 = R62 = R63 = R64 = R65 = R66 = R67 = R68 = R69 = R70 = R71 = R72 = R73 = R74 = R75 = R76 = R77 = R78 = R79 = R80 = R81 = R82 = R83 = R84 = R85 = R86 = R87 = R88 = R89 = R90 = R91 = R92 = R93 = R94 = R95 = R96 = R97 = R98 = R99 = R100 = R101 = R102 = R103 = R104 = R105 = R106 = R107 = R108 = R109 = R110 = R111 = R112 = R113 = R114 = R115 = R116 = R117 = R118 = R119 = R120 = R121 = R122 = R123 = R124 = R125 = R126 = R127 = R128 = R129 = R130 = R131 = R132 = R133 = R134 = R135 = R136 = R137 = R138 = R139 = R140 = R141 = R142 = R143 = R144 = R145 = R146 = R147 = R148 = R149 = R150 = R151 = R152 = R153 = R154 = R155 = R156 = R157 = R158 = R159 = R160 = R161 = R162 = R163 = R164 = R165 = R166 = R167 = R168 = R169 = R170 = R171 = R172 = R173 = R174 = R175 = R176 = R177 = R178 = R179 = R180 = R181 = R182 = R183 = R184 = R185 = R186 = R187 = R188 = R189 = R190 = R191 = R192 = R193 = R194 = R195 = R196 = R197 = R198 = R199 = R200 = R201 = R202 = R203 = R204 = R205 = R206 = R207 = R208 = R209 = R210 = R211 = R212 = R213 = R214 = R215 = R216 = R217 = R218 = R219 = R220 = R221 = R222 = R223 = R224 = R225 = R226 = R227 = R228 = R229 = R230 = R231 = R232 = R233 = R234 = R235 = R236 = R237 = R238 = R239 = R240 = R241 = R242 = R243 = R244 = R245 = R246 = R247 = R248 = R249 = R250 = R251 = R252 = R253 = R254 = R255 = R256 = R257 = R258 = R259 = R260 = R261 = R262 = R263 = R264 = R265 = R266 = R267 = R268 = R269 = R270 = R271 = R272 = R273 = R274 = R275 = R276 = R277 = R278 = R279 = R280 = R281 = R282 = R283 = R284 = R285 = R286 = R287 = R288 = R289 = R290 = R291 = R292 = R293 = R294 = R295 = R296 = R297 = R298 = R299 = R300 = R301 = R302 = R303 = R304 = R305 = R306 = R307 = R308 = R309 = R310 = R311 = R312 = R313 = R314 = R315 = R316 = R317 = R318 = R319 = R320 = R321 = R322 = R323 = R324 = R325 = R326 = R327 = R328 = R329 = R330 = R331 = R332 = R333 = R334 = R335 = R336 = R337 = R338 = R339 = R340 = R341 = R342 = R343 = R344 = R345 = R346 = R347 = R348 = R349 = R350 = R351 = R352 = R353 = R354 = R355 = R356 = R357 = R358 = R359 = R360 = R361 = R362 = R363 = R364 = R365 = R366 = R367 = R368 = R369 = R370 = R371 = R372 = R373 = R374 = R375 = R376 = R377 = R378 = R379 = R380 = R381 = R382 = R383 = R384 = R385 = R386 = R387 = R388 = R389 = R390 = R391 = R392 = R393 = R394 = R395 = R396 = R397 = R398 = R399 = R400 = R401 = R402 = R403 = R404 = R405 = R406 = R407 = R408 = R409 = R410 = R411 = R412 = R413 = R414 = R415 = R416 = R417 = R418 = R419 = R420 = R421 = R422 = R423 = R424 = R425 = R426 = R427 = R428 = R429 = R430 = R431 = R432 = R433 = R434 = R435 = R436 = R437 = R438 = R439 = R440 = R441 = R442 = R443 = R444 = R445 = R446 = R447 = R448 = R449 = R450 = R451 = R452 = R453 = R454 = R455 = R456 = R457 = R458 = R459 = R460 = R461 = R462 = R463 = R464 = R465 = R466 = R467 = R468 = R469 = R470 = R471 = R472 = R473 = R474 = R475 = R476 = R477 = R478 = R479 = R480 = R481 = R482 = R483 = R484 = R485 = R486 = R487 = R488 = R489 = R490 = R491 = R492 = R493 = R494 = R495 = R496 = R497 = R498 = R499 = R500 = R501 = R502 = R503 = R504 = R505 = R506 = R507 = R508 = R509 = R510 = R511 = R512 = R513 = R514 = R515 = R516 = R517 = R518 = R519 = R520 = R521 = R522 = R523 = R524 = R525 = R526 = R527 = R528 = R529 = R530 = R531 = R532 = R533 = R534 = R535 = R536 = R537 = R538 = R539 = R540 = R541 = R542 = R543 = R544 = R545 = R546 = R547 = R548 = R549 = R550 = R551 = R552 = R553 = R554 = R555 = R556 = R557 = R558 = R559 = R560 = R561 = R562 = R563 = R564 = R565 = R566 = R567 = R568 = R569 = R570 = R571 = R572 = R573 = R574 = R575 = R576 = R577 = R578 = R579 = R580 = R581 = R582 = R583 = R584 = R585 = R586 = R587 = R588 = R589 = R590 = R591 = R592 = R593 = R594 = R595 = R596 = R597 = R598 = R599 = R600 = R601 = R602 = R603 = R604 = R605 = R606 = R607 = R608 = R609 = R610 = R611 = R612 = R613 = R614 = R615 = R616 = R617 = R618 = R619 = R620 = R621 = R622 = R623 = R624 = R625 = R626 = R627 = R628 = R629 = R630 = R631 = R632 = R633 = R634 = R635 = R636 = R637 = R638 = R639 = （1）。 ​ ​ ​ （I） ​ R 1 and R 3 each independently of one another are a -(C6-C 20 )-heteroaryl group having at least 6 ring atoms; and R 2 and R 4 each independently of one another is -(Ci-C 12 )-alkyl; ​ ​ ​ ​ ​ ​ ​ ​

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