1032
Journal ofthe American ChemicalSociety
therefore contain larger error. (7) K. T. Suzuki, H. Yamada, and M. Hirobe. J. Chem. SOC.,Chem. Commun., 485 (1978). ( 8 ) NOTEADDED IN PROOF.After the manuscript was accepted, we measured the 13C NMR spectrum of [15N,]-9-ethyladenine in Me2S0 and found that the Ca signal appeared as a sharp singlet. This fact establishes that the unassigned coupling constant, 10.4 Hz, in the C8 signal in [ 15N]adenosine is J(CeN9) (Kainosho, Watanabe, and Kyogoku, unpublished results). Therefore, disappearance of splitting in the Ca signal of adenine derived from doubly enriched formamide is indeed due to the bond fission and re-formation of C-N bond during the thermal reaction, as Suzuki et al. have suggested.'
Masatsune Kainosho Central Research Laboratories, Ajinomoto Co, Inc. 1 - 1 Suzuki-cho, Kawasaki, 210 Japan Heceiced September 19, I978
1 101:4 /
February 14, 1979
Table 1. Hydrocarbon Oxidation with 2 and Iodosylbcnzenc substrate
products
yield, %"
0
55 15
/7i'h
6
14
A
82
I'h
1'11
I'h
trans-stilbcnc oxidc
Hydroxylation and Epoxidation Catalyzed by Iron-Porphine Complexes. Oxygen Transfer from lodosylbenzene Sir: The catalytic cycle of cytochrome P-450 is bclievcd to involvc reductivc activation of dioxygen a t the hcmc ccntcr and subsequent peroxy bond clcavagc to give a fcrryl ion specics as the active oxygen transfcr agent.',' Support for an iron--oxo species such as 1 is dcrivcd from thc fact that a number of single oxygcn donors, hydropcroxidcs, pcroxy acids, and iodosylbcnzcne, effect oxygcn transfcr in a manner similar in many rcspccts to thc fully reconstitutcd cnzymc system.' As part of our program to evaluatc simplc iron catalysts as oxygcn transfer agent^,^^,^ we have found that chloro-cu,~,y,6-tctraphcnylporphinatoiron( 111) (2) and chlorodimethylfcrriprotoporphyrin IX (3) catalyze the hydroxylation and cpoxidation of hydrocarbons with iodosylbcnzene as an oxygcn source.
-
0 7
P-450 Fc3+ 4P-450 * Fc3+ * H z 0 7 z c - . ?Ii'
+
H20 1 In a typical experimcnt solid iodosylbcnzene was added slowly to a solution of hydrocarbon and catalyst in methylenc chloride under nitrogcn a t room tcmperaturc. Rcsults for thc oxidation of a rcprcscntativc family of hydrocarbons arc givcn in Table I. Thus, cyclohexenc ( I mL, 9.8 mmol) and 2 (0.035 g, 0.049 mmol) were dissolvcd in 6 mL of methylene chloride. lodosylbcnzcnc (0.066 g, 0.3 mmol) was addcd to this mixturc ovcr a period of 30 min. The reaction mixture was diluted with cther, washed with sodium sulfitc, and analyzed by GLC. The yield of cyclohexcnc oxide was 55%)based on iodosylbenzenc. Cyclohcxenol ( I 5%) and a trace of cyclohcxcnone wcre thc only other organic products. Iodobcnzcne was rccovcrcd in quantitative yield. Similarly, cyclohcxadicne gave a 74% yield of the corresponding monocpoxidc. The reaction of cis- and trans-stilbene with iodosylbenzcne using 3 as a catalyst gave thc Corresponding cis- and trunsstilbcnc oxides. The complete rctcntion of configuration in this case contrasts with thc cpoxidation of cis- and trans-stilbene by tris(acetylacetonato)iron( I I I ) hydrogen peroxide which has been rcported to yield the trans epoxide from both starting materiakx Surprisingly, 2 catalyzed the conversion of cisstilbene to cis-stilbcnc oxide while thc trans isorncr was inert. Indeed, a mixture of the two olcfins led to efficient isolation of cis-stilbcne oxide (82%) and recovery of trans-stilbene! Such a dramatic changc in selectivity with changcs in the substitution pattcrn on the porphyrin suggests that the catalyst is intimately involvcd in the oxygcn transfer stcp.' Thc nature of this sclcctivity is not clcar, howcver. Space-filling models indicate that thc approach of thc double bond of cis-stilbcnc --*P-450 FeO'+
tracc
I'h
0002-7863/79/1501-1032$01 .OO/O
0
8
adarnantanc
1 -adarnantanol 2-adaniantanol
12 I
Yields bascd on iodosylbcnzcnc consurncd. Preliminary results indicatc that the lower yiclds with the less rcactivc hydrocarbons was due to cornpcting dcstruction of thc catalyst.
Tdbk 11. lntcrrnolccular vs. lntrarnokcular Oxidation of Octyl Estcrs
octyl acctatc 4
1.2
1,3
