References

 

Our Paper: Peng, F.; Danishefsky, S. J. J. Am. Chem. Soc. 2012, 134, 18860-18867.

For the application of Birch-type alkylation in natural product synthesis, the paper referenced:

Schultz, A. G.; Wang, A. J. Am. Chem. Soc. 1998, 120, 8259−8260.

This reaction involves the first asymmetric synthesis of a Hasubanan Alkaloid and the total synthesis of (+)-Cepharamine. The first asymmetric synthesis of (+)-cepharamine involves a  highly convergent strategy which results from an asymmetric Birch reduction-alkylation mechanism  and a radical cyclization reaction to change the C(9)-C(14) and C(12)-C(13) bonds. From there, a Birch reduction reaction occur  between chiral benzamide  with reagents  of potassium in NH3, THF, and tert-butyl alcohol (1 equiv) at -78 °C. It is then followed by an addition of LiBr where an alkylation reagent produced 95% yield of 1,4-cyclohexadiene 5 as a single diastereomer. Like the original mechanism, it involves a Birch reduction-alkylation reactions. A Birch Alkylation reaction  converts aromatic compounds into a 1,4-cyclohexadiene. NH3 in this reaction and LDA in the original reaction are amazing nucleophiles, that are able to donate its electrons. THF in both reaction  are great solvents to undergo the Birch reduction-alkylation reaction.

 

Articles that also cited this reference:

Citation 1:

Schultz, A. G.; Dai, M. Tetrahedron Letters 1999, 40, 645-648.

An asymmetric synthesis of the meloseine core structure 13 by utilization of the asymmetric Birch reduction-alkylation 2 -~ 3 to establish absolute configuration at C(20) of the alkaloid and the Mannich eyclizafion 9e ~ 10e to provide the c/s-pyrindm-6-one ring system. The revised of the asymmetric Birch reduction-alkylation can be seen in the mechanism in the original paper.

Citation 2:

Nicolaou, K. C.; Vourloumis, D.; Winssinger, N.; Baran, P. S. Angew. Chem. Int. Ed. 2000, 39, 44-122.

To be sure, the competitive nature of the pharmaceutical and biotechnology industries and their drive to discover and produce new cures for disease will demand new and sharper tools for organic synthesis. Fueled by these and other industries, the discipline of total synthesis will be there to attract talented individuals as practitioners and to deliver the new tools needed for yet higher efficiencies and selectivities. This article stresses the importance of total synthesis, thus relating back to the original  paper and its importance.

Citation 3:

Roche, S. P.; Jr. Porco, J. A. Angew. Chem. Int. Ed. 2011, 50, 4068-4093.

Schultz and co-workers, pioneers of the diastereoselective Birch reduction/alkylative dearomatization process, reported the first enantioselective synthesis of the alkaloid (+)-cepharamine. Relating this back to the original the reaction, it involves generating the enolate of 19, which underwent a 1,4 addition to the β-chloroenone function of 21.