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Polymenthylenebiphenyl polyanions by metallation—elimination
Tetrahedron Letters,Vo1.23,No.40,pp PrInted in Great Brltam
4077-4078,1982
0040-4(X9/82/404077-02$03.00/O 01982 Pergamon Press Ltd.
POLYMETtIYmBIPWENYLPOLYANIONSBY ~~T~ON-E~~~TION~ DieterWilhelm,TimothyClark,and Paul von Rag& Schleyer Institutfur UrganischeChermeder Frledrrch-Alexander-Universitat Erlangen-Nurnberg Henkestrasse42, D-8520Erlangen,FederalRepublicof Gerrrany SW
The 3,3~,5,51-tetramethyleneb~phenyl tetraanion,prepared311good y=ld by x&all-
ation-e11TIUniltion, gives tetrasubstituted biphenylderivatives, e.g., with H20, D20, methyl iodrde,and trlmethylsllyl chloride.The reactionsequence,startingfrom alkylatedcyclohexanones,providesa generalsyntheticmute to symmetrical polysubstrtuted biphenyls. tCombmed metallation-elm tion (reactionwith excess 1 1 n-butyllithium/potassium hydrocarbons, although amylate)'is a potentiallyvaluablesyntheticroute to polyunsaturated to give biphenyl1s a good example. the choiceof precursormay be critical.Arormatisatlon Phenylcyclohexane IS easilymetallatedto give a benzylanion but does not undergoelation which cannotform a stabilisedbenzylanion,gives a 50% yield to brphenyl.1-Phenylcyclohexene, of blphenyl,togetherwrth unchangedstartingmaterial.Bis-cyclohexylidene leads only to a 25% yield,but bls-fl-cyclohexenyl) (I, n=O) elates
smoothly(80%)to biphenyl(III,n=O)
To explorethe syntheticutrlityof this reactIon,we prepareda numberof dlenes,I, by 3 pinacolreaction*of the readilyavallablesethylcyclohexanones and subsequentdehydration. 'Ihedienes,I, were reactedwith excess (see Table) BuLr/KOtAmreagent'1~1hexaneat room temperature(24 h) followedby reflux (20 h), polyan~_ons (II)resultedwhen methylgroups were present.Quenchulgwith water gave the methylatedbiphenyls(III),normallyavailable throughlow yield couplulgreactionsof methylatedhalobenzenes.4 TABLE.Yields of blphenylproductsby metallat~on-elunination. ProductBlphenyls(III)a Moles Excess BuL&KOtAm Reagent MetaXation-elm Biphenyl
6
80
4,4'-D~~hy~lphenyl
8
57b
3,3'-D~~hylbiphenyl 2,2'-D~thy~b~phenyl
8 8
80 2!?
3,3',5,5'-Tetramethylb1phenyl
10
95
a Identifiedby comparisonwith comnericalsamplesor literatuzedata tolyl-1-methylcyclohexene (28%). %~or
tion Yield (%)
prcxiuct: 4077
startmg m&erial.
4,5 b
By-product 4-p-
4078
Surprasmngly, Meta methyl groupsfavor elxxnatxon, but ortho methylsare unfavorable. the hrghlycharged3,3',5,5'-tetramethyleneb1phenyl "tetraanlon" (II, n=2) 1s formedIIIkrgher yield than any of the formaldlanlons.Littleuse has been made of such mtermedlates synthfZt1cally heretofore.6 TetraanxonII (n=Z),whxh can also be obtainedby dxrectmetallattlon of 3,3',5,5'-te~~ethy~~p~ny~, gives the tetradeutemderxvatlve(90%)wsth I&O. Addltlonof an excessof methyl lodldeto IV at -40' C followedby slow warrmngand 6 hr stlrrvlgat room tqrature,
gave a noteworthyyield (90%, based on startmg dxene)of 3,3',5,5'-tetraethylbl-
phenyl.'ReactIonwith ~~thylsllyl
chloridealso proceedssmcothly(68% yield) to the 7 corresponding tetra-trxxthylsllyl derlvatlve. The above sequencethus providesaccessto syrurtstrlcally methylatedand to alpha-substlt-
uted polymethylbrphenylsstartrngfrom avaxlablemethylcyclohexanones. Acknowledgements. This work was supportedby the DeutscheForschungsgememschaft and the For& der Chemxchen Indust-rle. ~C~~N~S 1) The Metallatlon-ElLminatlon Reaction.III. Part I, T Clark and P.v.R.Schleyer,J Chem. SOC., them. colxmun., 198 (1976);part II, D. Wilhelm,T. Clark,T. Frledl,and P.v.R. Schleyer,Chem. Ber, 115, IIIpress (198'2). 2) E.B. Earnet?and C.A. Lawrence,J. Chem. Sot., 1104 (1961). 3) D.S Grexdingerand D. Gxnsburg,J. Org. Chem.,26, 2633 (1960, A. Mandelbaumand M. Cax, Ibid.,-22, 1406 (1957). 4) II.Hasegawa,M. Imanarr,and K. Ishlzu,Bull. Chem. Sot. Japan,45_,1153 (1972),K. Ishlzu, K. M&al, H Hasegawa,K. Kubo, H. Nlshlguchr,and Y. Deguchl,Ibxd.,4&
2808 (19691,K.
Ishxzu,Y. INUX, K. Modal,H. Sh&ata, and Is.Hasegawa,IbId.,43_,3956 (19701,K. Ishlzu, H. Hasegawa,H. Chikakl,Y. Nxhrgucti, and Y. hguchl, Kog yo KagakuZasshl,68, 1522 (1965). 5) J. Blum, D. Ml&tern, and Y. Sasson,J. Org. Chem.,2, 3233 (19701,G. Kortumand H. M3ler, '2,Phys. Chem.,I, 207 (1956). 6) For tetracarbanlons, see L. A. Paquette,G.D. Ewmg, and S. G. Traynor,J. Am Chem. Sot., E,
279 (19761,L. A. Paquetie,G. D. Ewmg, S. Traynor,and J.M Gardlrk,IbId.,99_,6115
(19771,V.R. Sandel,B. Belmky, T. Stefanlak,and D. Krerl,J. Org. Chem.,s,
2116 (1975),
K. Mullen,J. Oth, H. Engels,and E. Vogel,Angew. Chem. Int. Ed. Engl.,18, 229 (1979), W. H&r,
K. MUlen, and 0. Wennerstrom,lbld.,19, 624 (19801,R.B. Bates,B.A. Hess, Jr.,
C.A. Ogle, and L.J. Schaad,J. Am. Chem. Sot.,2,
5052 (19811,A. Mvlsky,A,Y. Meyer,and
M. Rabmowltz, rbid.,x, 2475 (1982). 7) M.p. 84.6', 'H-nmr (CC14) 6 = 0.00 (s, 36H, SlCH3),2 05 (s, 88, CH2), 6 45 (m, ZH, 4,4'-ArH),6.85 (4H, 2,2',6,6'-A&),IR @BP): 3010, 2960, 2925, 2880 (CH),MS (7Oe-V). m/e = 498 (loo%),483 (13%),430 (78%),410 (53%),358 (47%),344 (34%).Anal. C,H. (Received in Germany 21 July 1982)
4077-4078,1982
0040-4(X9/82/404077-02$03.00/O 01982 Pergamon Press Ltd.
POLYMETtIYmBIPWENYLPOLYANIONSBY ~~T~ON-E~~~TION~ DieterWilhelm,TimothyClark,and Paul von Rag& Schleyer Institutfur UrganischeChermeder Frledrrch-Alexander-Universitat Erlangen-Nurnberg Henkestrasse42, D-8520Erlangen,FederalRepublicof Gerrrany SW
The 3,3~,5,51-tetramethyleneb~phenyl tetraanion,prepared311good y=ld by x&all-
ation-e11TIUniltion, gives tetrasubstituted biphenylderivatives, e.g., with H20, D20, methyl iodrde,and trlmethylsllyl chloride.The reactionsequence,startingfrom alkylatedcyclohexanones,providesa generalsyntheticmute to symmetrical polysubstrtuted biphenyls. tCombmed metallation-elm tion (reactionwith excess 1 1 n-butyllithium/potassium hydrocarbons, although amylate)'is a potentiallyvaluablesyntheticroute to polyunsaturated to give biphenyl1s a good example. the choiceof precursormay be critical.Arormatisatlon Phenylcyclohexane IS easilymetallatedto give a benzylanion but does not undergoelation which cannotform a stabilisedbenzylanion,gives a 50% yield to brphenyl.1-Phenylcyclohexene, of blphenyl,togetherwrth unchangedstartingmaterial.Bis-cyclohexylidene leads only to a 25% yield,but bls-fl-cyclohexenyl) (I, n=O) elates
smoothly(80%)to biphenyl(III,n=O)
To explorethe syntheticutrlityof this reactIon,we prepareda numberof dlenes,I, by 3 pinacolreaction*of the readilyavallablesethylcyclohexanones and subsequentdehydration. 'Ihedienes,I, were reactedwith excess (see Table) BuLr/KOtAmreagent'1~1hexaneat room temperature(24 h) followedby reflux (20 h), polyan~_ons (II)resultedwhen methylgroups were present.Quenchulgwith water gave the methylatedbiphenyls(III),normallyavailable throughlow yield couplulgreactionsof methylatedhalobenzenes.4 TABLE.Yields of blphenylproductsby metallat~on-elunination. ProductBlphenyls(III)a Moles Excess BuL&KOtAm Reagent MetaXation-elm Biphenyl
6
80
4,4'-D~~hy~lphenyl
8
57b
3,3'-D~~hylbiphenyl 2,2'-D~thy~b~phenyl
8 8
80 2!?
3,3',5,5'-Tetramethylb1phenyl
10
95
a Identifiedby comparisonwith comnericalsamplesor literatuzedata tolyl-1-methylcyclohexene (28%). %~or
tion Yield (%)
prcxiuct: 4077
startmg m&erial.
4,5 b
By-product 4-p-
4078
Surprasmngly, Meta methyl groupsfavor elxxnatxon, but ortho methylsare unfavorable. the hrghlycharged3,3',5,5'-tetramethyleneb1phenyl "tetraanlon" (II, n=2) 1s formedIIIkrgher yield than any of the formaldlanlons.Littleuse has been made of such mtermedlates synthfZt1cally heretofore.6 TetraanxonII (n=Z),whxh can also be obtainedby dxrectmetallattlon of 3,3',5,5'-te~~ethy~~p~ny~, gives the tetradeutemderxvatlve(90%)wsth I&O. Addltlonof an excessof methyl lodldeto IV at -40' C followedby slow warrmngand 6 hr stlrrvlgat room tqrature,
gave a noteworthyyield (90%, based on startmg dxene)of 3,3',5,5'-tetraethylbl-
phenyl.'ReactIonwith ~~thylsllyl
chloridealso proceedssmcothly(68% yield) to the 7 corresponding tetra-trxxthylsllyl derlvatlve. The above sequencethus providesaccessto syrurtstrlcally methylatedand to alpha-substlt-
uted polymethylbrphenylsstartrngfrom avaxlablemethylcyclohexanones. Acknowledgements. This work was supportedby the DeutscheForschungsgememschaft and the For& der Chemxchen Indust-rle. ~C~~N~S 1) The Metallatlon-ElLminatlon Reaction.III. Part I, T Clark and P.v.R.Schleyer,J Chem. SOC., them. colxmun., 198 (1976);part II, D. Wilhelm,T. Clark,T. Frledl,and P.v.R. Schleyer,Chem. Ber, 115, IIIpress (198'2). 2) E.B. Earnet?and C.A. Lawrence,J. Chem. Sot., 1104 (1961). 3) D.S Grexdingerand D. Gxnsburg,J. Org. Chem.,26, 2633 (1960, A. Mandelbaumand M. Cax, Ibid.,-22, 1406 (1957). 4) II.Hasegawa,M. Imanarr,and K. Ishlzu,Bull. Chem. Sot. Japan,45_,1153 (1972),K. Ishlzu, K. M&al, H Hasegawa,K. Kubo, H. Nlshlguchr,and Y. Deguchl,Ibxd.,4&
2808 (19691,K.
Ishxzu,Y. INUX, K. Modal,H. Sh&ata, and Is.Hasegawa,IbId.,43_,3956 (19701,K. Ishlzu, H. Hasegawa,H. Chikakl,Y. Nxhrgucti, and Y. hguchl, Kog yo KagakuZasshl,68, 1522 (1965). 5) J. Blum, D. Ml&tern, and Y. Sasson,J. Org. Chem.,2, 3233 (19701,G. Kortumand H. M3ler, '2,Phys. Chem.,I, 207 (1956). 6) For tetracarbanlons, see L. A. Paquette,G.D. Ewmg, and S. G. Traynor,J. Am Chem. Sot., E,
279 (19761,L. A. Paquetie,G. D. Ewmg, S. Traynor,and J.M Gardlrk,IbId.,99_,6115
(19771,V.R. Sandel,B. Belmky, T. Stefanlak,and D. Krerl,J. Org. Chem.,s,
2116 (1975),
K. Mullen,J. Oth, H. Engels,and E. Vogel,Angew. Chem. Int. Ed. Engl.,18, 229 (1979), W. H&r,
K. MUlen, and 0. Wennerstrom,lbld.,19, 624 (19801,R.B. Bates,B.A. Hess, Jr.,
C.A. Ogle, and L.J. Schaad,J. Am. Chem. Sot.,2,
5052 (19811,A. Mvlsky,A,Y. Meyer,and
M. Rabmowltz, rbid.,x, 2475 (1982). 7) M.p. 84.6', 'H-nmr (CC14) 6 = 0.00 (s, 36H, SlCH3),2 05 (s, 88, CH2), 6 45 (m, ZH, 4,4'-ArH),6.85 (4H, 2,2',6,6'-A&),IR @BP): 3010, 2960, 2925, 2880 (CH),MS (7Oe-V). m/e = 498 (loo%),483 (13%),430 (78%),410 (53%),358 (47%),344 (34%).Anal. C,H. (Received in Germany 21 July 1982)