Julia—Kocienski olefination

Modified one-pot Julia olefination to give predominantly ( )-olefins from het-eroarylsulfones and aldehydes. A sulfone reduction step is not required. 

The use of larger counterion (such as K ) and polar solvents (such as DME) favors an open transition state (PT = phenyltetrazolyl)  

Name Reactions A Collection of Detailed Mechanisms and Synthetic Applications, DOI 10.1007/978-3-319-03979-4 144, Springer International Publishing Switzerland 201 

Alonso, D. A. Fuensanta, M. Najera, C. Varea, M. J. Org. Chem. 2005, 70,6404. Rong, F. Julia Lythgoe olefination. In Name Reactions for Homologations-Part L, Li, J. J., Ed. WUey Hoboken, NJ, 2009, pp 447 73. (Review). 

Name Reactions, 4th ed., DOI 10.1007/978-3-642-01053-8 135, Springer-Verlag Berlin Heidelberg 2009 

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The Julia olefination involves the addition of a sulfonyl-stabilized carbanion to a carbonyl compound, followed by elimination to form an alkene.277 In the initial versions of the reaction, the elimination was done under reductive conditions. More recently, a modified version that avoids this step was developed. The former version is sometimes referred to as the Julia-Lythgoe olefination, whereas the latter is called the Julia-Kocienski olefination. In the reductive variant, the adduct is usually acylated and then treated with a reducing agent, such as sodium amalgam or samarium diiodide.278... 

Plesniak K, Zarecki A, Wicha J (2007) The Smiles Rearrangement and the Julia-Kocienski Olefination Reaction. 275 163-250 Polito M, see Braga D (2005) 254 71-94 Poulin-Kerstien AT, see Dervan PB (2005) 253 1-31... 

An inverse olefination protocol based on the intennediate 6 has appeared in the patent literamre recently (nucleophilic activation for Julia-Kocienski olefination) ... 

The Julia-Kociensky Olefination is an alternative procedure, which leads to the olefin in one step. 

Selective chemical transformations can also be performed on the natural product sanglifehrin A (1) itself [19]. It is surprising that C26-C27 of 1 can be chemoselectively cis-dihydroxylated (Sharpless conditions) in a yield of 70%. The natural product can afterwards be reassembled by Julia-Kocienski olefination. The success of this operation indicates that total syntheses of sanglifehrin A (1) alternative to those by Nicolaou et al. and Paquette should be worth pursuing. 

The fact that the Julia-Lythgoe olefination requires more than one step to prepare alkenes has generally been accepted as an inconvenient and inevitable part of the procedure developed by Marc Julia and Basil Lythgoe. This flaw kept nagging at Marc Julia s brother Sylvestre, who would not rest until he had found the one-step (Sylvestre) Julia olefination. The (Sylvestre) Julia-Kocienski olefination has become the state-of-the-art-variant of this olefination (Figure 11.23). It may be applied to any kind of aldehyde. 

Marc) Julia-Lythgoe- and (Sylvestre) Julia-Kocienski Olefination... 

Fig. 11.23. Julia-Kocienski olefination to obtain tmns-alkenes from aldehydes in a single step their condensation reaction with the sulfonyl anion B, followed by an Ar-SN reaction (- E) and a fragmentation.

The Smiles Rearrangement and the Julia-Kocienski Olefination Reaction... 

In a pivotal modification of the direct olefination reaction Kocienski and his coworkers [10] showed that the use of l-phenyl-lff-tetrazol-5-yl sulfones, preferentially with NaHMDS or KHMDS as the base and DME as the solvent, provides olefins in excellent yields and stereoselectivity with respect to -isomers. The modified version of the direct olefination reaction has frequently been referred to as the Julia-Kocienski olefination reaction. 

Table 10 Heterocyclic and aromatic sulfones used in the Julia-Kocienski olefination reaction ...

Table 11 Typical conditions for Julia-Kocienski olefination, sulfones, bases, solvents and the temperature...

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