| abstract |
The invention relates to a phosphine compound of the formula (1): wherein R<sup>1</sup> is a linear or branched alkyl group having 1 to 5 carbon atoms or a cyclohexyl group; R<sup>2</sup> and R<sup>3</sup> represent independently a hydrogen atom or an alkyl group having 1 to 5 carbon atoms; R<sup>4</sup> , R<sup>5</sup> , R<sup>6</sup> and R<sup>7</sup> represent independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms and a di-alkyl amino group, each of the alkyl group having 1 to 5 carbon atoms; X represents a functional group that may form a stable bond with phosphorous atom; and with the proviso that a ring or condensed ring may be formed between the members of at least one pair selected from the group consisting of R<sup>4</sup> and R<sup>5</sup>, R<sup>5</sup> and R<sup>6</sup>, and R<sup>6</sup> and R<sup>7</sup>. |