B-allenyl- and B-(gamma-trimethylsilylpropargyl)-10-phenyl-9-borabicyclo[3.3.2]decanes: asymmetric synthesis of propargyl and alpha-allenyl 3-degree-carbinols from ketones
- PMID: 16928081
- PMCID: PMC2597672
- DOI: 10.1021/ol061596j
B-allenyl- and B-(gamma-trimethylsilylpropargyl)-10-phenyl-9-borabicyclo[3.3.2]decanes: asymmetric synthesis of propargyl and alpha-allenyl 3-degree-carbinols from ketones
Abstract
Simple and efficient Grignard procedures are reported for the syntheses of B-allenyl-10-(phenyl)-9-borabicyclo[3.3.2]decane (1) and its B-(gamma-trimethylsilylpropargyl) counterpart (2) in both enantiomeric forms. Both add selectively to ketones, providing propargyl- and alpha-silylallenyl 3-degree-carbinols, respectively (i.e., 6 (61-93% ee) and 9 (64-98% ee)). The air-stable boron byproduct is efficiently recovered and recycled back to either 1 or 2. The ozonolysis and bromination of 9 provide nonracemic alpha-hydroxy acids and gamma-bromopropynyl carbinols, respectively.
References
-
-
Hernandez E, Soderquist JA. Org Lett. 2005;70:5397.Lai C, Soderquist JA. Org Lett. 2005;7:799.See also: Burgos CH, Canales E, Matos K, Soderquist JA. J Am Chem Soc. 2005;127:8044.
-
-
- Ikeda N, Arai I, Yamamoto H. J Am Chem Soc. 1986;108:483–486. - PubMed
- Haruta R, Ishiguro M, Ikeda N, Yamamoto H. J Am Chem Soc. 1982;104:7667–7669.
- Corey EJ, Yu C-M, Lee D-H. J Am Chem Soc. 1990;112:878.
- Brown HC, Khire UR, Narla G. J Org Chem. 1995;60:8130.
- Kulkarni SV, Brown HC. Tetrahedron Lett. 1996;37:4125.
-
-
For racemic processes, see: Zweifel G, Backlund SJ, Leung T. J Am Chem Soc. 1978;100:5561.Wang KK, Nikam SS, Ho CD. J Org Chem. 1983;48:5376.Wang KK, Liu C. J Org Chem. 1985;50:2578.Brown HC, Khire UR, Narla G. J Org Chem. 1995;60:8130. With chiral substrates, see: Alcaide B, Almendros P, Aragoncillo C, Rodriguez-Acebes R. J Org Chem. 2001;66:5208.
-
-
- Canales E, Prasad G, Soderquist JA. J Am Chem Soc. 2005;127:11572. - PubMed
-
- Short RP, Masamune S. J Am Chem Soc. 1989;111:1892.
Publication types
MeSH terms
Substances
Grants and funding
LinkOut - more resources
Full Text Sources
