A general metal-free approach for the stereoselective synthesis of C-glycals from unactivated alkynes

• Shekaraiah Devari,
• Manjeet Kumar,
• Ramesh Deshidi,
• Masood Rizvi and
• Bhahwal Ali Shah

Beilstein J. Org. Chem. 2014, 10, 2649–2653, doi:10.3762/bjoc.10.277

• , India 10.3762/bjoc.10.277 Abstract A novel metal-free strategy for a rapid and α-selctive C-alkynylation of glycals was developed. The reaction utilizes TMSOTf as a promoter to generate in situ trimethylsilylacetylene for C-alkynylation. Thanks to this methodology, we can access C-glycosides in a

• single step from a variety of acetylenes , i.e., arylacetylenes and most importantly aliphatic alkynes. Keywords: α-selective; C-alkynylation; glycal; metal free; TMSOTf; Introduction C-Glycosides represent an important class of carbohydrate mimics, owing to their presence in a large number of

• biologically active natural products, such as palytoxin, spongistatin, vitexin, orientin, bergenin and halichondrin [1][2][3][4][5]. Over the years myriad methods have appeared for their efficient and stereoselective synthesis [6][7][8][9][10][11][12]. Among these methods, C-alkynylation [13][14][15][16] is of

C–C (alkynylation) vs C–O (ether) bond formation under Pd/C–Cu catalysis: synthesis and pharmacological evaluation of 4-alkynylthieno[2,3-d]pyrimidines

• Dhilli Rao Gorja,
• K. Shiva Kumar,
• K. Mukkanti and
• Manojit Pal

Beilstein J. Org. Chem. 2011, 7, 338–345, doi:10.3762/bjoc.7.44