Proazaphosphatrane P(RNCH 2 CH 2 ) 3 N (R=Me, i‐ Pr)‐Catalyzed Isomerization of Allylaromatics, Allyl Phenyl Sulfide, Allyl Phenyl Sulfone, and bis ‐Allylmethylene Double Bond‐Containing Compounds

Using a proazaphosphatrane catalyst, P(RNCH 2 CH 2 ) 3 N (R=Me, i‐ Pr), allylaromatics and allyl phenyl sulfide were selectively isomerized to the corresponding vinyl isomers in yields up to >99% in CH 3 CN at 40 °C. Efficient transformation of allyl phenyl sulfone at ambient temperature afforded an isomerization/dimerization product in >95% yield. Conjugation of bis ‐allylmethylene double bond‐containing compounds gave the corresponding conjugated isomers for cis , cis ‐9,12‐octadecadienol and its methyl ether in yields up to 97%, and desilylation/conjugation products were obtained from the catalytic reaction of the trimethylsilyl ether of cis , cis ‐9,12‐octadecadienol. The reaction mechanism is discussed based upon the 1 H and 31 P NMR‐monitored reactions in CD 3 CN or CH 3 CN under the reaction conditions.