Abstract: The present invention relates to a coupling method between intramolecular carbon using the intramolecular cyclization reaction in situ of an allyl-indium compound derived from an allyl derivative containing an unsaturated hydrocarbon compound and indium, in presence of a transition metal compound catalyst. More particularly, the present invention relates to a coupling method between intramolecular carbon for preparing a cyclic compound having a vinyl group as a substituent by bonding a carbon in an allyl derivative containing an unsaturated hydrocarbon compound and a carbon in the unsaturated hydrocarbon compound via intramolecular cyclization reaction in situ of an allyl-indium compound as a coupling agent derived from the allyl derivative containing the unsaturated hydrocarbon and indium (In), in presence of a palladium catalyst.