Sl. Hart et al., Ti(eta(5)-C5H5)(eta(5)-(C5H4Bu)-Bu-t)(CH2Ph)(2); a probe of the course of the petasis benzylidenation reaction, SYNLETT, (1), 1999, pp. 90-92
The existence of the proposed benzylidene intermediate 11 in the Petasis be
nzylidenation procedure is supported by the isolation of cyclometallated pr
oduct 8. A model is proposed which explains the empirical observation that
a large acid residue and a small ester group are needed for good stereosele
ctivity in benzylidenation reactions.