McMurry’s reagent

Crucially, it was found22 that upon reaction of the vinylketene complex 42.a with 1-pentyne, the same product distribution was seen as for the direct thermolysis of 1-pentyne with the precursor carbene 43.a. The analysis was simplified by reduction of the crude reaction mixture with McMurry s reagent to produce a mixture of the isomeric indanols 44-46. 

The reduction of TiCls with 4 eq. of LiAlH4 in THF gives a fine black suspension of a titanium(II) species. A 4 1 ball-milled mixture of TiCls and L1A1H4 is available from Alfa Inorganics ( McMurry s Reagent )- Addition of this stable solid to THF leads to evolution of hydrogen and formation of titanium(II). 

Another unique method for the synthesis of [6]paracyclophane derivatives was developed by Tochtermann, which was based on the deoxygenation of oxepinophane using the McMurry s reagent (Scheme 5) [13]. The oxepinophane... 

McMurry s reagent, 369 Macrocyclic annulenes, 117-118 Magic Acid, 271 Magnesium, 218... 

Titanium(ni) chloride-Lithimn aluminum hydride, 6, 588-589, Supplier Alfa ( McMurry s Reagent ). 

Dehalogenation coupling of allyi or benzyl halides or of aryl gem-dihalo-alkenes. Olah and Prakash have reported further uses of McMurry s reagent to effect these reactions. 

Gassman et al have published full details of their work on the synthesis of fused cyclopropanes by reaction of l-chloro-2-alkylcycloalkenes with organo-lithium reagents (see Vol. 4, p. 244), and further aspects of the synthesis of cyclopropanes from 1,3-diols using McMurry s reagent have been reported. ... 

Markovnikov addition 85 Matteson reaction 7181 Matteson s reagent 7241 McMurry coupling 17,658,6661, 671... 

The olefin metathesis of 3-hydroxy-4-vinyl-l,2,5-thiadiazole 112 and a McMurry coupling reaction (Ti3+ under reductive conditions) of the aldehyde 114 were both unsuccessful <2004TL5441>. An alternative approach via a Wittig reaction was successful. With the use of the mild heterogenous oxidant 4-acetylamino-2,2,6,6-tetramethyl-piperidine-l-oxoammonium perfluoroborate (Bobbitt s reagent), the alcohol 113 was converted into the aldehyde 114. The phosphonium salt 115 also obtained from the alcohol 113 was treated with the aldehyde 114 to give the symmetrical alkene 116 (Scheme 16) <2004TL5441>. 

Cyclocarbonylation (9, 205-206). McMurry and Andrus have examined the scope of the reaction of Collman s reagent with unsaturated tosylates as a route to cycloalkanones and have concluded that the reaction is useful for preparation only of cyclopentanones and cyclohexanones from olefinic tosylates in which the double bond is monosubstituted. Yields are higher with primary tosylates than with secondary tosylates. 

M. B. Smith, J. March in March s Advanced Organic Chemistry, 5,h ed., John Wiley and Sons, Inc., New York, 2001, p. 1561 T. Laue, A. Plagens, Named Organic Reactions, John Wiley and Sons, Inc., New York, 1998, pp. 184-187 See McMurry Reagent... 

Wynberg studied stereochemistry of the McMurry reductive dimerization of camphor in detail (64). In Scheme 37, A and B are homochiral dimerization products derived by the low-valence Ti-promoted reduction, while C and D are achiral heterochiral dimers. The reaction of racemic camphor prefers homochiral dimerization (total 64.9%) over the diastereomeric heterochiral coupling (total 35.1 %). Similarly, as illustrated in Scheme 38, oxidative dimerization of the chiral phenol A can afford the chiral dimers B and C (and the enantiomers) or the meso dimer D. In fact, a significant difference is seen in diastereoselectivity between the enaritiomerically pure and racemic phenol as starting materials. The enantiomerically pure S substrate produces (S,S)-B exclusively, while the dimerization of the racemic substrate is not stereoselective. In the latter case, some indirect enantiomer effect assists the production of C, which is absent in the former reaction. Thus, it appears that, even though the reagents and reaction conditions are identical, the chirality of the substrate profoundly affects the stability of the transition state. 

Cycloheptenol in glyme added to titanium(II) reagent prepared from TiClg and LiAlH4 in glyme under Ng, and refluxed 16 hrs. -V 3-(2-cycloheptenyl)cyclo-heptene. Y 87%. F. e. s. J. E. McMurry and M. Silvestri, J. Org. Chem. 40, 2687 (1975). 

Some recent highlights include adaptation of Katritzky s benzo-triazole syntheses to ether preparation , generation of acyl radicals by carbonylation , and oxidative ring closures with Fe(C104)3 (as an alternative to the harsher Mn(III) route) . Bis(phosphonium) anhydrides are finding diverse applications, and a number of new vanadium reagents have materialized, e.g. a V(II) complex dimer for cross-coupling of aldehydes as an alternative to the McMurry route . ... 

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