B-alkyl Suzuki-Miyaura

Potuzak, J. S. Tan, D. S. Synthesis of Cl-alkyl and acylglycals from glycals using a B-alkyl Suzuki-Miyaura cross coupling approach. Tetrahedron Lett. 2004, 45, 1797-1801. 

This chemistry features in a synthesis of the left hand fragment of yessotoxin and adriatoxin <02OL3943>. Assembly of the F-N ring component of gymnomycin A, involves a b-alkyl Suzuki-Miyaura coupling reaction <02OL1747>. 

Chemler, S. R., Trauner, D., Danishefsky, S. J. The B-alkyl Suzuki-Miyaura cross-coupling reaction development, mechanistic study, and applications in natural product synthesis. Angewandte Chemie, International Edition 2001,40,4544-4568. 

Anticipating a B-alkyl Suzuki-Miyaura cross-coupling reaction between the Cl-Cl 4 and C15-C24 subunits, alcohol 57 was smoothly converted to vinyl iodide 60 in seven steps, including a Pt02 reduction of the crowded triple bond of intermediate 59, without overreduction. The coupling of the vinyl iodide 60 and C15-C24 subunit was performed by using trialkyl boronate species 61, prepared from alkyl iodide 46, under [Pd(dppf)Cl2] and AsPhs conditions to afford the DDM backbone 62 in 60% yield (Scheme 14). Finally, after carbamate formation and total deprotection, DDM 1 was obtained in 70% yield. The spectroscopic and analytical data of the synthetic samples of as well as their in vitro cytotoxicity levels were in full accord with those of the natural product reported in the literature. 

SCHEME 14 B-alkyl Suzuki-Miyaura cross-coupling reaction between the C1-C14 and C15-C24 subunits 60 and 61. 

Liu, Y., Wang, J., Li, H., Wu, )., Feng, G and Dai, W.-M. (2010) Synthesis of the C7-C23 fragment related to iriomoteolide-la via B-alkyl Suzuki-Miyaura cross-coupling and indium-mediated aldehyde allylation. Synlett., 2184-2188. 

Preparation and B-alkyl-Suzuki-Miyaura Cross-coupling Reactions of Functionalized Alkyl Trifluoroborates... 

Suzuki and Miyaura first demonstrated the utility of B-alkyl-9-BBN derivatives for coupling with vinyl halides (Figure 28.4). ° The reaction conditions are mild enough to tolerate many functional groups such as esters, nitriles, amides, amines, and sulfides and a wide variety of compounds (e.g., 119a-e) have been synthesized using this protocol (Figure 28.5). 

Synthesis of the C9-C28 spiroacetal fragment of didemnaketal B was achieved using a similar strategy. Suzuki-Miyaura coupling of an alkyl borate (derived from iodide 102 and B-methoxy-BBN) to the phosphate 103 afforded endocyclic enol ether 104. Spirocyclization took place after cleavage of the silyl ethers with subsequent treatment with mild acid (PFTS), affording the doubly anomerically stabilized spiroacetal 105 in high yield. 

On the other hand, Waldmann, Arndt, and co-workers succeeded in the assembly of biphenomycin B 11 via an early stage Suzuki-Miyaura coupling and a macrolactam-ization (Scheme 4.5). ° Their synthesis was also initiated by the PTC-catalyzed asymmetric alkylation. Treatment of... 

Alkyl halides typically undergo P-elimination under the cross-coupling conditions, and are used less frequently than the vinyl/aryl halides. Suzuki and Miyaura were successful in coupling the alkyl iodides with boranes such as 5-phenyl-9-BBN 155 and B-octyl-9-BBN 157 in the presence of Pd(PPh3)4 to obtain the C(sp -sp )-coupled products 156 and 158 (Scheme 1 >.AA)P... 

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