Jacobi synthesis

The authors are grateful for financial support from the Swiss National Science Foundation, National Centre of Competence in Research Chemical Biology—Visualisation and Control of Biological Processes Using Chemistry (to PJD) and Dr. J. Jacobi Trust (to PNS). The authors thank Tse Wong for technical assistance, Maxime Dubois for the help in the synthesis of the compounds and Dr. Lucienne Juillerat-Jeanneret (Institute of Pathology, CHUV, Lausanne, Switzerland) for providing the MDA-MB-231 cells. 

Jacobi and coworkers used an oxy-Cope/Diels-Alder sequence to synthesize the tumor inhibitor gnididione (4-234) [80]. A similar sequence was also used by Kraus and coworkers for the synthesis of 11-deoxydaunomycinone (4-235) [81]. 

Jacobi von Wangelin A, Neumann H, Gcirdes D, Beller M (2004) In Beller M, Bolm C (eds) Transition metals for organic synthesis. Wiley, Weinheim, p 133... 

Beak P, Johnson TA, Kim DD, Lim SH (2003) Enantioselective Synthesis by Lithiation Adjacent to Nitrogen and Electrophile Incorporation. 5 139-176 Behr A, Turkowski B, Roll R, Schdbel R, Henze G (2008) Multiphase Catalysis in Temperatme-Dependent Multi-Component Solvent (TMS) Systems. 23 19-52 Bellemin-Laponnaz S, see Gade LH (2006) 22 117-157 Beller M, see Jacobi von Wangelin A (2006) 18 207-221 Beller M, see Striibing D (2006) 18 165-178... 

A. Jacobi, D. Seebach, How to Stabilize or Break P-Peptidic Helices by Disulfide Bridges Synthesis and CD Investigation of P-Peptides with Cysteine and Homocysteine Side Chains Helv. Chim. Acta 1999, 82, 1150- 1172. 

D. Seebach, A. Jacobi, M. Rueping, K. Gademann, M. Ernst, B. Jaun, Synthesis of p-Hexa-and P-Heptapeptides Containing Novel p - -Amino Acids with Two Serine or Two Cysteine Side Chains - CD- and NMR-Spectroscopic Evidence for 3 4-Helical Secondary Structures in Water , Helv. Chim. Acta 2000, 83, 2115 - 2140 and in Hominatio - An International Tribute to Albert Eschenmosef , (Ed. M.V. Kisakurek), Wiley-VCH, Weinheim, 2001. 

Jacobi extended this methodology for the synthesis of the novel sesquiterpene ( )-paniculide A (528) (Scheme 66) (84TL4859). Thermal cycloaddition of 518 in ethylbenzene in a similar condition afforded the methoxyfuran 520 in 94% yield through the intermediate 519. Phenylselenation of 520 with LDA and phenylselenyl chloride gave a 1 1 mixture of phenylselenides 521, which upon kinetic deprotonation-protonation afforded the a-isomer (522) in... 

Jacobi s synthesis of ( )-paniculide-A involves an intramolecular Diels-Alder reaction of the alkynic ketone (31). This compound was prepared in >90% yield (Scheme 9) by acylation of a lithium alkynide with the A7-methoxy-A7-methylamide (30). Addition of the anion to other derivatives related to (30) such as an acid chloride, a trifluoroacetic mixed anhydride, an acyl imidazole, S-(2-pyridyl) thiolates and a mixed carbonic anhydride (from ethyl chloroformate) led to either bis-addition or to proton abstraction. Notice should be made of the stability exhibited by the A7-methoxy-A7-methylamide group while the oxa-zole moiety was being introduced. ... 

The Nicholas reaction was used to synthesize the p-lactam precursor of thienamycin in the laboratory of P.A. Jacobi and thereby accomplish its formal total synthesis. The necessary p-amino acid was prepared by the condensation of a boron enolate (derived from an acylated oxazolidinone) with the cobalt complex of an enantiopure propargylic ether. The resulting adduct was oxidized with ceric ammonium nitrate (CAN) to remove the cobalt protecting group from the triple bond, and the product was obtained with a 17 1 anti.syn selectivity and in good yield. 

Jacobi, P. A., Zheng, W. Enantioselective synthesis of p-amino acids using the Nicholas reaction. Enantioselective Synthesis of fi-Amino Acids 1997, 359-372. 

For more information on the Takasago (-)-menthol synthesis, see H. Kumobayashi, Reel. Trav. Chim. Pays-Bas, 1996,115, 201 C. Chapuis and D. Jacoby, Appl. Catal. A, 2001, 221, 93 and G. P. Chiusoli and P. M. Maitlis, Metal-Catalysis in Industrial Organic Processes, RSC Publishing Cambridge, 2006, pp. 103-107. 

Jacoby (187) and the Hamilton group (188-191) suggested that bis- or tris-aromatic residues could serve as scaffolds for helical mimetics. Che et al. have examined a variety of aromatic-based scaffolds as potential helix mimetics (192). Rebek and coworkers have suggested a central pyridazine ring (193) as well as a heterocyclic piperazine-based scaffold (194). Ahn and Han developed a facile synthesis of benzamides as potential helix mimetics (195). 

Acetylenic cobalt complexes greatly facilitate the heterolytic cleavage of adjacent alcohols or ethers. On treatment with Lewis acids, these complexes afford cobalt stabilized carbenium ions, which can be captured by nucleophiles such as enolates. Jacobi and Zheng have employed chiral boron enolates of Evans s oxa-zolidinone 6.91 (R = i-Pr). After removal of the chiral auxiliary, they obtained anti adds 11.43 with a high selectivity [1677] (Figure 11.9). The reaction can be extended to the boron enolates of related oxazolidinones and to a-branched propargyl derivatives. This reaction has been applied to the synthesis of P-aminoacids after Curtius rearrangement and oxidation of the triple bond [1677]. 

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