A Tale of 2 Cycles

Figure 1. 2 catalytic cycles crossing path – the plan. (Taken from Ref. [2])

If you have read my article on ‘Atom Economy’ before [1], you should see why this publication by Professor Trost’s group is fascinating[2]. The article asks the question: what will happen when 2 useful catalytic cycles cross path (Figure 1) [2]?


Figure 2. Sum is greater than the parts – the work of 2 catalysts to provide useful structures. (Take from Ref. [2])

While one may speculate a myriad of products is the result, the group has shown us that by careful design the outcome can be extremely useful (Figure 2) [2]. By using a vanadium catalyst for the atom-economical Meyer-Schuster type reaction [3], and a Palladium catalyst for the Tsuji-Trost reaction. By combining the 2 catalytic cycles together, useful ‘allylated, α, β-unsaturated ketones’ can be achieved (Figure 2, 3) [2]. Figure 3 shows the 3 possible scenarios involving the 2 intriguing catalytic cycles [2]. This should serve as great inspirations for multi-catalytic reactions.


Figure 3. The products formed from using one / both of the catalysts. (Taken from Ref. [2])

Reference:

1. For my article ‘Atom Economy’ on 13th June 2010, please see:
http://emockscience.blogspot.com/2010/06/c-6-carbons-12-carbons-18-carbons-waste.html

2. Contemporaneous Dual Catalysis by Coupling Highly Transient Nucelophilic and Electrophilic Intermediates Generated in Situ
Barry M. Trost and Xinjun Luan
Journal of America Chemical Society
DOI: 10.1021/ja110501v

3. Victorio Cadierno, Pascale Crochet, Sergio E. García-Garrido, José Gimeno
Dalton Trans., 2010, (17),4015-4031