General approach to the synthesis of .alpha.-patchoulane

William F. Erman, and Logan C. Stone. J. Am. Chem. Soc. , 1971, 93 (11), pp 2821–2823. DOI: 10.1021/ja00740a061. Publication Date: June 1971. ACS Le...
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solution. These compounds revert t o the yellow species, [{(.?r-C5Hs)Ru(CO)z}2X]PF6 (X = Br and C1) at room temperature in both solution and in the solid state and consequently could not be obtained analytically pure. The infrared spectra of these green complexes correspond with those of the yellow [ { (7r-C5H5)R U ( C O ) ~ ) ~ X ] P(X F ~ = Br and C1) and thus these green compounds are proposed to be a second isomeric form of [ { (.rr-C5H5)Ru(C0)2}zX]PF6. The green and yellow isomers of [{(?r-C5H6)Ru(CO)z)2X]PF6 (X = Br and C1) are very susceptible to nucleophilic attack and react readily with a wide range of anions. For instance, treatment of [ { (n-CjHj> R U ( C O ) ~ ) ~ X ] P(X F ~= Br and C1) in solution with halides and pseudohalides e.g., C1-, Br-, I-, CN-, SCN-, and N3-, readily leads t o the formation of neutral products according to the scheme

the infrared spectrum of one of the phenyl being P bonded to the wich structure shown zwitterionic species.'

of this derivative is indicative rings of the tetraphenylboron ruthenium a t ~ m . ~The ? ~ sand(1) is thus proposed for this

( 5 ) M. J. Nolte, G . Gafner, and L. M. Haines, Chem. Commun., 1406 (1969); L. M. Haines, Inorg. Chem., in press. (6) R. R . Schrock and J. A. Osborn, ibid., 9,2339 (1970). (7) Although a number of R h and Ir derivatives containing a tetraphenylboron anion directly bonded to the metal atom through an arene ring have recently been reported,5,6 compounds with sandwich structures which contain this ligand are not known.

R. J. Haines* Research and Process Decelopment South African Iron and Steel Industrial Corporatiori Ltd. Pretoria, Republic of South Africa

A. L. du Preez

+ Y- +

[ ( ( * G H ~ ) R U ( C O )1,%XI+

+

( T - C ~ H : ) R U ( C O ) ~ X ( T-CSHS)RU(CO)~Y

Department of Inorganic and Analytical Chemistry Unicersity of Pretoria, Pretoria, Republic of South Africa Receiced March 22, 1971

The cations [{(.rr-CSHj)R~(CO)2}ZX]+ (X = Br and Cl) also react readily with the anion, tetraphenylboron, in solution. Fission of a boron-carbon bond in General Approach to the Synthesis of B(C6H5)4-and transfer of a phenyl group to a ruthenium a-Patchoulane Sesquiterpenes. The Intramolecular atom is effected and the products ( P - C ~ H ~ ) R U ( C O ) ~ XLewis Acid Catalyzed Addition of and ( P - C ~ H ~ ) R U ( C O ) ~ - U - C obtained. ~H~ The anion Diazo Ketones to Olefins B(C4H&- is attacked in an analogous manner. Although mercury salts are known to cleave boron-carbon Sir: bonds, reactions involving the transfer of a phenyl The presence of a wide variety of sesquiterpenes group from boron to a transition metal atom are not which possess the a-patchoulane skeleton 1 in patchouli well documented. Two isolated examples are the slow oi1,I Indian valarian root oil,* and various cyperus H & cis-Ptformation of trans-Pt { P ( C Z H ~ ) B } ~ ( C ~from oils3 has been reported, but evaluation of the odor { P(CZH5)3)zC12 and NaB(C6H& in refluxing tetrahyand flavor of many of these sesquiterpenes has been drofuran3 and the reaction of [Pt{P(CH3)2C6H5)2limited due t o the lack of synthetic means for attaining (CH30H)CH3]+ with NaB(C6H& in solution to give working quantities of these compounds. Although ~ ) Z .cyanide and trans-Pt { P ( C H ~ ) Z C ~ H ~ } Z ( C ~ HThe not a phenyl group is extracted from B(C6H5)3CN- specific syntheses of individual a-patchoulane type sesquiterpenes*-+ have been recorded, it was the objective on reaction with [ { ( T - C ~ H ~ ) R ~ ( C O ) ~ (X ) ~ X=] + Br and Cl); ( T - C ~ H ~ ) R U ( C O and ) ~ X( T - C ~ H ~ ) R U ( C O ) ~ C Nof our work to develop a general synthetic approach which would be adaptable t o all of the sesquiterpenes are formed as products. in this series. We record here such a general, albeit The reaction of (d2jH5)Ru(C0)zCl with NaBmultistep, approach to the a-patchoulane skeleton (CBH& in ethanol under reflux is also observed to afford the u-phenyl derivative (P-C~H~)RU(CO)~-U-using as the target compounds the sesquiterpenes dlC s h . The corresponding reaction involving ( T (1) N. Tsubaki, K . Nishimura, and Y . Hirose, Bull. Chem. SOC.J a p . , C5Hj)Ru(P ( C ~ H & ) Z C does ~ not afford (n-C5H5)Ru(P40, 597 (1967). (C&)3]2-u-Cd%, however. A product shown not to (2) C. S. Narayanan, I