112379-71-2Relevant academic research and scientific papers
SOLVOLYTIC REARRANGEMENT STUDIES WITH (E)- AND (Z)-2-ANISYL-1,2-DITOLYLVINYL BROMIDES
Lee, Choi Chuck,Wanigasekera, Dave
, p. 933 - 940 (2007/10/02)
Reaction of (E,Z)- or (E)-2-anisyl-1,2-ditolylvinyl bromides ((E,Z)- or (E)-6-Br-2-13C) with HOAc-AgOAc gave a 1:1 mixture of (E)- and (Z)-2-anisyl-1,2-ditolylvinyl acetates ((E,Z)-6-OAc-1,2-13C), with about 37.4percent scrambling of the label from C-2 to C-1 arising from degenerate 1,2-anisyl shifts in the 2-anisyl-1,2-ditolylvinyl cation (6-2-13C).No detectable amount of 1-anisyl-2,2-ditolylvinyl acetate was formed, indicating no nondegenerate 1,2-tolyl shift in cation 6 to give the more stable 1-anisyl-2,2-ditolylvinyl cation (10) in the reaction with HOAc-AgOAc.Reaction of (E)-6-Br-2-13-C with 2,2,2-trifluoroethanol (TFE) in the presence of 2,6-lutidine gave as major product 1-anisyl-2,2-ditolylvinyl 2,2,2-trifluoroethyl ether (10-OTFE-1,2-13C) and a 1:1 mixture of (E)- and (Z)-2-anisyl-1,2-ditolylvinyl 2,2,2-trifluoroethyl ethers ((E,Z)-6-OTFE-1,2-13C) as minor products, the ratio of 10-OTFE to (E,Z)-6-OTFE being about 80:20.Scrambling on the 13C label in the major product, 10-OTFE-1,2-13C, was 48.8 +/- 0.9percent and scrambling in the minor products, (E,Z)-6-OTFE-1,2-13C, was 47.2 +/- 1.4percent.The present work with cation 6 completes the series of nine possible triarylvinyl cations, with various combinations of phenyl (Ph), p-tolyl (Tol), and (or) p-anisyl (An) as the three aryl groups, that can give rise to degenerate 1,2-aryl shifts across the double bond, and the present results are discussed in conjunction with data from previous work on the other eight triarylvinyl cationic systems.
