Mechanism of rearrangement of an allylvinylrhenium complex to an (allyl vinyl ketone)rhenium complex: role of concerted organometallic reactions in avoiding high-energy coordinatively unsaturated intermediates

Low-valent Organorhenium Compounds

“…The less congested allyl methyl complex analogue of (103) exists as a 7:1 equilibrium mixture with an r| 3 -allyl acetyl complex (104). 220 These results support a mechanism for the conversion of (100) to (101), in which two consecutive concerted organometallic rearrangements occur. The vinyl migration to CO is assisted by r\ l -to T| 3 -allyl rearrangement, and coupling of the allyl and acyl ligands is facilitated by complexation of the vinyl double bond.…”

“…287 For comparison AG t = 34.7 kJ mol" 1 for rotation of the T| 2 -ethene ligand in [Re(CO) 2 (rj 2 -CH 2 CH 2 )(Cp)]. 220 The rhenium(III) if-alkyne complexes [ReC^if-R'C^CR^ri-Cp*)] (R'=R 2 = Ph, Me, Et; R 1 = Ph, R 2 = Me) (146) exhibit a rich reactivity including alkyne-allyl 288 and alkyne-alkene 289 coupling reactions as shown in Scheme 38. Treatment of (146) with CH 2 =CHCH 2 MgCl at -78 °C followed by thermolysis in toluene gives the 2,4-pentadienylrhenium(III) complex (147) in 70-80% yield.…”

Synthesis of Functionalized Deuterioallylic Compounds

“…Such compounds are potential useful reagents to prepare other selectively labeled species or to precise the reactions pathways of reactions both with and without an allylic transposition . Deuterioallylic alcohols are easily formed by reduction of the corresponding acrylaldehyde or acrylic esters, no isomerization occurring even in the presence of strong Lewis bases. However, starting from these alcohols, approaches involving substitution reactions only led to mixtures of isomers of the expected product.…”

Preparation of Novel Dideuterioallyl Mercaptan

“…Neithr compound has been reported in the literature. One of the logical schemes for the synthesis is to preparing corresponding allyl alcohol (2) and converting it to the corresponding mercaptan. Allyl alcohol-d 5 (CD 2 =CDCD 2 OH) is commercially available, but the -1,1-d 2 or -2,3-d 2 alcohol is not.…”

“…Allyl alcohol-1,1-d 2 has been reported to be prepared by reduction of acryloyl chloride with LiAlD 4 . 2 There are numerous citations of the use of LiAlH 4 for the reduction of α,β-unsaturated carboxylic acids to alkenols. For example, a reference book states that lithium aluminum hydride reduces exclusively the carbonyl group, even in an unsaturated acid with α,β-conjugated double bonds.…”