PDDA products, at best, in marginal yields. As mentioned above,
this finding may be caused by the CT character of the long-
wavelength transition of these compounds. The irradiation results
of ketones 7a and 7b confirm that turning to esters was a good
decision.
In summary, we report a conceptually novel synthetic route to
1,19-binaphthyls by the irradiation of propargyl and homopro-
pargyl esters of 3-arylpropiolic acids. Investigations towards the
atropselective synthesis of binaphthyls are currently under way.
Notes and references
1 (a) K. C. Nicolaou, H. Li, C. N. C. Boddy, J. M. Ramanjulu, T.-Y. Yue,
S. Natarajan, X.-J. Chu, S. Bra¨se and F. Ru¨bsam, Chem.–Eur. J., 1999, 5,
2584; (b) K. C. Nicolaou, C. N. C. Boddy, S. Bra¨se and N. Winssinger,
Angew. Chem., Int. Ed., 1999, 38, 2097.
2 (a) P. Kocovsky, S. Vyskocil and M. Smrcina, Chem. Rev., 2003, 103,
3213; (b) R. Noyori, Adv. Synth. Catal., 2003, 345, 15.
3 J. M. Brunel, Chem. Rev., 2005, 105, 857; J. M. Brunel, Chem. Rev., 2005,
105, 4233.
4 R. Noyori, Chem. Rev., 1988, 98, 2405.
Scheme 3 Photochemical behavior of esters 5 and ketones 7.
5 I. Cepanec, Synthesis of Biaryls, Elsevier, Amsterdam, 2004.
6 Classical methods for biaryl synthesis. (a) Ullmann reaction: F. Ullmann,
Chem. Ber., 1896, 29, 1878; F. Ullmann, Justus Liebigs Ann. Chem., 1904,
332, 38; F. Ullmann and J. Bielecki, Chem. Ber., 1901, 34, 2174;
P. E. Fanta, Chem. Rev., 1946, 38, 139; P. E. Fanta, Chem. Rev., 1964, 64,
613; P. E. Fanta, Synthesis, 1974, 9; (b) Pschorr cyclization: R. Pschorr,
Chem. Ber., 1896, 29, 496; (c) Gomberg–Bachmann–Hey reaction:
M. Gomberg and W. E. Bachmann, J. Am. Chem. Soc., 1924, 46, 2339;
D. H. Hey, G. H. Jones and M. J. Perkins, J. Chem. Soc. D, 1970, 1438;
(d) Gatterman sythesis: E. R. Atkinson, H. J. Lawler, J. C. Heath,
E. H. Kimball and E. R. Read, J. Am. Chem. Soc., 1941, 63, 730;
E. R. Atkinson and J. J. Lawler, Org. Synth. Coll. Vol. I, 1941, 222; (e)
Thermolysis of diaroylperoxides: D. F. DeTar, R. A. J. Long,
J. Rendleman, J. Bradley and P. Duncan, J. Am. Chem. Soc., 1967, 89,
4051; D. F. DeTar, J. Am. Chem. Soc., 1967, 89, 4058; M. M. Henry,
J. M. Dou, G. Vernin and J. Metzger, Bull. Soc. Chim. Fr., 1971, 4593.
7 (a) P. Wessig, G. Mu¨ller, A. Ku¨hn, R. Herre, H. Blumenthal and
S. Troelenberg, Synthesis, 2005, 1445; (b) P. Wessig, G. Mu¨ller, R. Herre
and A. Ku¨hn, Helv. Chim. Acta, 2006, in press.
Table 3 Irradiation conditions and product yields of compounds
8–11
Reactant
Solventa
X
R
Productsb
5a
5b
5c
5d
5e
A
A
A
A
A
A
A
M
M
O
O
O
OCH2
OCH2
OCH2
OCH2
CH2
H
8a (38%), 9a (41%)
8b (46%)
10a (36%)
8c (41%), 9b (30%)
10b (36%), 11a (23%)
8d (38%)
10c (28%)
10d (18%)
8d (13%), 9c (17%)
OMe
OMe
H
H
5f
OMe
OMe
OMe
H
5g
7a
7b
a
CH2CH2
b
A 5 acetone, M 5 methanol. Irradiation conditions. Starting
concentration: 0.01 M, light source: high-pressure mercury arc lamp
(150 W, Heraeus), irradiation time: 15–20 h (TLC monitoring).
8 K. Sonogashira, Y. Tohda and N. Hagihara, Tetrahedron Lett., 1975, 16,
4467.
9 M. Yamaji, J. Kobayashi and S. Tobita, Photochem. Photobiol. Sci.,
2005, 4, 294.
(46%) and 8d (38%) were obtained in satisfactory yields. In
contrast, compounds 5c and 5g, bearing a 3-(2-methoxy-naphth-1-
yl)-propiolic ester moiety, showed low reactivity and afforded
4526 | Chem. Commun., 2006, 4524–4526
This journal is ß The Royal Society of Chemistry 2006