Organometallics 1996, 14, 4975-4976
4975
Selenoarsenation of Alkynes Takahiro Kanda, Tadashi Koike, Susumu Kagohashi, Kazuaki Mizoguchi, Toshiaki Murai, and Shinzi Kato* Department of Chemistry, Faculty of Engineering, Gifu University, 1-1 Yanagido, Gifu 501-11, Japan Received September 1, 1995@ Summary: Carboxylic diphenyhrsinous anhydroselenides were treated with phenylacetylene under reflux in benzene for 20 h to give the corresponding (E)-addition products i n the range of 40-90% isolated yields with complete regio- and stereoselectivity. During the course of our studies on selenoic acid esters with a bond between selenium and a heavy heteroatom, we confirmed that selenoic acid Se-arsanyl esters can be prepared and easily handled in air without appreciable decomp~sition.l-~ This has prompted us to examine the reactivity of the Se-As bond toward C-C unsaturated bond^.^>^ In this communication we describe the first example of selenoarsenation of alkynes with complete regio- and stereoselectivity (eq 1). 0 R1%eAsPh2 1
+
r R
2
0
1
R1
R2
2,
%b
4-MeCeH4,
2
3 4 5
6 7 8 9 10
4-BrCeH4 n-Pr Me2N
.
AsPhp
R' K S e / = ( R 2
R'= 4-MeC&,4-Bc6H4, R2= aryl, vinyl, alkynyl
entry
aConditions: 1 (0.5 mmol), alkyne (0.5 mmol), benzene (2 mL), reflux, 20 h. blsolated yield. %eaction was carried out at 20 "C. *en= npentyl.
80 "C, 20 h in CsHe
Table 1. Selenoarsenation of Alkynes"
(1 1
2 n-Pr, Me2N
Table 1 summarizes our results on the selenoarsenation of conjugated alkynes. In one such reaction, an equimolar mixture of la and phenylacetylene was stirred in benzene a t reflux for 20 h. Removal of the Abstract published in Advance ACS Abstracts, November 1,1995. (1)(a) Kageyama, H.; Kido, K.; Kato, S.; Murai, T. J. Chem. Soc., Perkin Trans. 1 1994, 1083. (b) Kato, S.; Kageyama, H.; Kawahara, Y.; Murai, T.; Ishihara, H. Chem. Ber. 1992, 125, 417. (c) Kato, S.; Ibi, K.; Kageyama, H.; Ishihara, H.; Murai, T. Z. Naturforsch. 1992, @
47B, 558.
(2)(a) Kanda, T.; Mizoguchi, K.; Koike, T.; Murai, T.; Kato, S. Synthesis 1994, 282. (b) Kanda, T.; Mizoguchi, K.; Koike, T.; Murai, T.; Kato, S. J. Chem. Soc., Chem. Commun. 1993, 1631. (3) For reviews on organoarsenic selenium derivatives: (a)du Mont, W. W.; Hensel, R.; Kubiniok, S.; Lange, L. In The Chemistry of Organic Selenium and Tellurium Compounds; Patai, S., Rappoport, Z., Eds.; John Wiley & Sons: New York, 1987; Vol. 2, Chapter 15, pp 591-656. (b) Barton, D. H. R.; Dadoun, H.; Gourdon, A. Nouu. J . Chim. 1982,6, 53. (c) Dehnert, P.; Grobe, J.; Hildebrandt, W.; Van, Duc le 2. Naturforsch. 1980,35B, 149. (d) Chen, G. C.; Daniel, J. R.; Zingaro, R. A. Carbohydr. Res. 1976, 50, 53. (e) Chen, G. C.; Zingaro, R. A,; Thompson, C. R. Carbohydr. Res. 1975, 39, 61. (0 Anderson, J. W.; Drake, J. E.; Hemmings, R. T.; Nelson, D. L. Inorg. Nucl. Chem. Lett. 1975, 11, 233. (g) Sagan, L. S.; Zingaro, R. A.; Irgolic, K. J. J . Organomet. Chem. 1972,39,301. (4) Heats of dissociation of the Se-As bond in AsSe and AszSe3 are quite low (22.2 and 39.1 kcal/mol, respectively): Pelevin, 0. V.; Mil'vidskii, M. G.; Belyaev, A. H.; Khotin, B. A. Izu.h a d . Nauk. S S S R Neorg. Mater. 1966,2, 942; Chem. Abstr. 1966, 65, 4721d. (5) To the best of our knowledge, no examples of additions of As-S, As-Se, and As-Te bonds to C-C unsaturated compounds have been reported. For examples of additions of As-Y bonds ( Y heteroelement) to olefins see the following. (a) Y = As: Cullen, W. R.; Dhaliwal, P. S.; Styan, G . E. J.Organomet. Chem. 1966, 6, 364. (b) Cullen, W. R.; Hota, N. K. Can. J . Chem. 1964,42, 1123. For examples of addition to acetylenes see the following. (c) Y = As: Cullen, W. R.; Styan, G. E. Can. J . Chem. 1966,44, 1225. (d) Y = Si: Cullen, W. R.; Dawson, D. S.; Styan, G . E. Can. J . Chem. 1965,43, 3392.
solvent and subsequent recrystallization (hexane/CHnClz = 1/1)gave the addition product 2a in 93% isolated yield (entry 1h6 lH and 13C NMR studies showed that adduct 2a was a single isomer (of four possible regioand stereoisomers). In a difference NOE experiment, irradiation of the singlet a t 6 7.18corresponding to the vinylic proton gave 9% and 5% enhancement of only the aromatic protons at 6 7.45-7.61 (multiplet) and 6 7.67 (doublet), respectively (Figure l).7This suggests that both the arsenic and selenium substituents are attached to the internal and terminal carbon atoms of the (6) A typical procedure for selenoarsenation of alkynes (entry 1in Table 1)follows: Into a dried, two-necked flask (10mL) equipped with a reflux condenser were placed l a (0.5 mmol), phenylacetylene (0.5 mmol), benzene (2 mL), and a magnetic stirring bar. The mixture was heated under reflux for 20 h and concentrated in vacuo. The lH and 13C NMR spectra (CDC13) of the resulting crude product depicted the formation of a single isomer (E-addition product). By recrystallization with a mixed solvent [CHzClhexane = 111 (2 mL)], 2a (0.47 mmol, 93%)was obtained pure as pale yellow needles. (7) Spectral data for 2a are as follows: pale yellow needles; mp 8992 "C; IR (KBr) 1689 (C=O), 1654 (C-C) cm-l; 'H NMR (CDC13,270 ~ ) , (d, J = 8.2 Hz, 2H, M e c a d ) , 7.18 MHz) 6 2.33 (s, 3 H, C H ~ C B H7.16 (s,1 H, =CH), 7.21-7.29 (m, 5 H, Ph), 7.33-7.43 (m, 6 H, AsPh), 7.457.61 (m, 4 H, AsPh), 7.67 (d, J = 8.2 Hz, 2 H, MeCa4); 13C NMR (CDC13, 68 MHz) 6 21.7, 126.7, 127.4, 127.5, 127.6, 128.4, 128.8, 129.5, 134.0, 136.0, 138.5, 142.3, 144.4, 144.9, 191.6; MS (CI, re1 int, %) mle 529 Pose, M+ 1, 100). Anal. Calcd for C2sHZdsOSe: C, 63.53; H, 4.38. Found: C, 63.56; H, 4.31. (8) In order to grow larger crystals, a portion was dissolved in a small amount of ethyl acetate (0.5 mL), and to this hexane (1.5 mL) was carefully added to form a layer under an argon atmosphere. Crystals for X-ray structural analysis were obtained. (9) Selected crystallographic data for 2a (C28HZ&OSe; M, = 529.37): 141/a (No. 88, triclinic), a = 40.86(2)A, c = 6.021(2)A, V = 10052(19) A3, Z = 16, p = 1.399 g ~ m -p(Mo ~ , Ka)28.18 cm-l, R (R,) = 0.056 (0.082). A total of 5285 reflections (28" = 55.0")were collected on a Rigaku AFC7R diffractometer at 296 K using Mo K a radiation ( A = 0.710 69 A); an absorption correction using the program DIFABS was applied that resulted in transmission factors ranging from 0.58 to 1.19. The structure was solved by direct methods (SHELXS86)with the C, 0, As, and Se atoms refined anisotropically.
+
Q276-7333l95/2314-4975$Q9.QQlQ 0 1995 American Chemical Society
4976 Organometallics, Vol. 14, No. 11, 1995
A
Me
Figure 1. Enhancement of the peaks by irradiation of the vinylic proton of 2a in lH NMR. ,-
C
c7
x
Figure 2. ORTEP drawin of the molecular structure of 2a. Selected bond lengths ( ) and bond angles (deg): C1-
C2 1.34(2),Asl-C1 1.96(1),Cl-C3 1.49(2),Sel-C2 1.89(l),ASl-Cl5 1.95(1), ASl-CS 1,96(1),014221 1.15(2); Asl-Cl-C3 114(1),kSl-Cl-C2 122(1),Sel-C2-C1124(l),C1-Asl-C9 102.9(6),C9-Asl-Cl5 96.961, C2-SelC21 93.2(7), Sel-C21-01 123(1). starting acetylene with E-stereochemistry. This structure was confirmed by an X-ray single-crystal diffraction analysis (Figure 2L8p9 The X-ray structure reveals that the vinylic structure of 2a is distorted because of steric repulsion between the substituents.1° The selenoarsenation of aromatic acetylenes proceeded smoothly at reflux in benzene until the ester la (10)Such a distorted structure is readily confirmed by the torsion angles [Sel-C2-Cl-Asl = 170.2", 01-C21-Sel-C2 = 4(2)"1.
Communications was completely consumed, whereas similar reactions a t 20 "C resulted in recoveries of la (30-40%, entries 1, 3,4). In the case of 1-ethynylcyclohexene,the addition went to completion even a t 20 "C (entry 6). In the reactions with conjugated enynes and diynes, the corresponding dienes 2e,f and enyne 2g were obtained selectively, indicating that the olefinic and internal acetylenic hctionalities remained intact, respectively (entries 5-7). 4-Bromobenzoyl (lh),butyroyl (li),and carbamoyl derivatives (lj)were suitable reagents for the selenoarsenation, affording the corresponding addition products 2h-j in modest isolated yields (entries 8-10). The structures of products 2b-j also were determined by NOE studies similar to that with 2a (Supporting Information). Unfortunately, similar reactions of the esters 1 with olefins and terminal alkynes conjugated to electron-withdrawing groups such as carbonyl or nitrile hardly proceeded. In summary, we have found that selenoic acid Searsanyl esters add t o terminal alkynes conjugated with an olefinic, aromatic, or acetylenic substituent in refluxing benzene with complete regio- and stereoselectivity. The selenoarsenation reaction is a useful addition to synthetic organoarsenic and organoselenium chemistry.
Acknowledgment. We thank Dr. Ebihara and Prof. Kawamura of Gifu University for helpful assistance with X-ray analysis. This work was supported by the Grant-in-Aid for Scientific Research (B) (No. 06453127) and partially by the Grant-in-Aid for Scientific Research on Priority Area of Reactive Organometallics (No. 07216228) from the Ministry of Education, Science, Sports and Culture of Japan. Supporting Information Available: Text giving experimental details and characterizationdata for lb-d and 2b-j and listings of crystallographic data (positional and thermal parameters and bond distances and angles) and a packing diagram for the addition product 2a (13 pages). This material is contained in many libraries on microfiche, immediately follows this article in microfilm version of the journal, can be ordered from ACS, and can be downloaded from the Internet; see any current masthead page for ordering information and Internet access instructions.
OM950692D
