Trisannelated Benzenes by Cyclotrimerization of Bromostannylalkenes

Abstract

COMMUNICATIONS 1,l-Bis(iodozincio)ethane (9) reacted with cinnamyl chloride (2a) to give the organozinc intermediate 10, which yielded the deuteriodezincated product (10, D in place of ZnI) in 65 % yield. The direct coupling of 10 with the ally1 bromide 7b did not occur. In this case, the copper-mediated reactionls] gave the double coupled product 11 in 66 % yield [Eq. (4)].

Synthesis of ‘thianthrene dimer’ by the coupling reaction of stannylthianthrenes in the presence of copper catalysts

“…4.14.5. (R,S) (S,R)-1-(10-S-Monoxythianthrene-1-yl)thianthrene-10-S-monoxide (12). X-ray crystal data; empirical formula: C 24 H 14 O 2 S 4 ; formula weight 462.61; crystal system¼monoclinic; space group C2/c(#15); lattice parameters: a¼36.36 (2) A; b¼7.682…”

“…In our initial experiment, we attempted to synthesize the thianthrene oxide dimers, (R,S) (S,R)-1-(10-S-monoxythianthrene-1-yl)thianthrene-10-S-monoxide (12) or (R,R) (S,S)-1-(10-S-monoxythianthrene-1-yl)thianthrene-10-S-monoxide (13) from thianthrene dimer 3. When 3 was allowed to react with 3-chloroperbenzoic acid (m-CPBA) at 0 C in CH 2 Cl 2 , the reaction proceed smoothly and crude 1 H NMR spectrum showed that the crude product of their oxide dimers contain an inseparable byproduct.…”

“…Recently, Ogawa et al 9b reported the synthesis of 1,9 0 -disubstituted thianthrene by Negishi coupling reaction. Meanwhile, on the coupling reaction of aryl groups, 10,11 alkynyl, 10 alkenyl, 10,12 and vinyl 13 groups via stannanes in the presence of Cu(NO 3 ) 2 $3H 2 O. It is well known that the protocols were highly effective and versatile, another using copper catalysts, such as Cu(NO 3 ) 2 $3H 2 O and CuCl, were used in THF or DMF condition.…”

Palladium-catalyzed Trimerization of Strained Cycloalkynes: Synthesis of Decacyclene

“…It occurred to us that a more aryne-like cyclopentyne, such as acenaphthyne (14), might be more easily trimerized. Although recent calculations have shown that 14 is very highly strained, 18 it is one of the few arynes to have been characterized spectroscopically, Chapman and coworkers having recorded its infrared and UV spectra by irradiation of 1,3-bis(diazo)phenalen-2-one with UV light (>274 nm) in an argon matrix.…”

“…13 Although the above compounds may formally be considered as oligomers of the corresponding cycloalkyne, this does not mean that free cycloalkynes are involved in their formation. 14 We decided to start our study with the trimerization of a six-membered cycloalkyne, cyclohexyne (2). To keep the reaction conditions as close as possible to those previously used for the trimerization of arynes we selected triflate 1 as the alkyne precursor.…”