ChemInform Abstract: Synthesis of the Butatriene C₄ Function: Methodology and Applications

Abstract

Review: 239 refs.

1,4‐Dialkynylbutatrienes: Synthesis, Stability, and Perspectives in the Chemistry of carbo‐Benzenes

“…The latter was prepared by a procedure described by Stachulski and co-workers, [8] which is based on the use of a mixture of CCl 4 and PPh 3 in acetonitrile as a specific solvent. This method was reported to be particularly efficient with ketone substrates, and here afforded the gem-dichloroenyne 5 b in 88 % yield from ketone 3 (Scheme 2, bottom).…”

“…Previously described procedures were used for the preparation of 8, [12] 10, 12, and 13. [13,14] Experimental details for compounds 3,4,16,17,18,19,26, and 27 are available in the Supporting Information. All reactions were carried out under nitrogen or Argon using Schlenk and vacuum line techniques.…”

“…The resulting mixture was stirred for 50 min at À78 8C, then MeI (0.95 mL, 15.18 mmol) was added and stirring was continued for 30 min at À78 8C and for 75 min at RT. The mixture was diluted with diethyl ether and treated with saturated aqueous NH 4 Cl. The aqueous layer was extracted two times with diethyl ether, and the combined organic layers were washed with brine, dried over MgSO 4 , and evaporated under reduced pressure.…”

“…Beyond (and related to) the carbo-benzene series, the family of functional 1,4-diA C H T U N G T R E N N U N G alkynylbutatrienes is hereafter extended to representatives stabilized by non-alkynyl substituents, in particular, with R = Ph or CF 3 . Their synthesis is undertaken by either classical methods used for the preparation of generic butatrienes, [4] that is, R'Li/CuX-mediated reductive coupling of gem-dihaloalkenes, or SnCl 2 /HClmediated reduction of 1,4-dioxy-but-2-yne precursors (Scheme 1).…”

“…The working electrode was either a Pt microdisk (0.5 mm diameter) or a glassy carbon microdisk (1 mm diameter). The supporting electrolyte [nBu 4 6 ] (Fluka, 99 % electrochemical grade) was used as received and simply degassed under argon. Dichloromethane was freshly distilled prior to use.…”