[reaction: see text] The enantioselective [2 + 2] cycloaddition of alkynes possessing an ester functionality and norbornene derivatives proceeded efficiently using a chiral rhodium catalyst. The chiral tri- and tetracyclic cyclobutenes were obtained in moderate to high ee.

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Polyphenyl derivatives Q 0700 Rhodium-Catalyzed Enantioselective [2 + 2 + 2] Cycloaddition of Diynes with Unfunctionalized Alkenes. -(SHIBATA*, T.; KAWACHI, A.; OGAWA, M.; KUWATA, Y.; TSUCHIKAMA, K.; ENDO, K.; Tetrahedron 63 (2007) 52, 12853-12859; Dep. Chem. Biochem., Waseda Univ., Shinjuku, Tokyo 169, Japan; Eng.) -Klein 21-084 R 1