259874-44-7Relevant academic research and scientific papers
Structural diversification of the aminobicyclo[4.3.0]nonane skeleton using alkynylsilyl-derived allylic trichloroacetimidates
Mostafa, Mohamed A. B.,McMillan, Angus E.,Sutherland, Andrew
, p. 3035 - 3045 (2017/04/11)
The amino substituted bicyclo[4.3.0]nonane is a molecular scaffold found in a wide range of natural products and medicinal agents. Despite this, synthetic methods for the general preparation of this structural motif are sparse. Here we evaluate a diastere
Stereoselective synthesis of E,Z-configured 1,3-dienes by ring-closing metathesis. Application to the total synthesis of lactimidomycin
Gallenkamp, Daniel,Fuerstner, Alois
, p. 9232 - 9235 (2011/08/06)
Strategic positioning of a silyl group on the diene unit of a diene-ene substrate allows rigorous regio- and stereocontrol to be exerted during metathesis-based macrocyclization reactions. The versatility of this concise approach to E,Z-configured 1,3-die
1,2-Silyl-migrative cyclization of vinylsilanes bearing a hydroxy group: Stereoselective synthesis of multisubstituted tetrahydropyrans and tetrahydrofurans
Miura, Katsukiyo,Hondo, Takeshi,Okajima, Shigeo,Nakagawa, Takahiro,Takahashi, Tatsuyuki,Hosomi, Akira
, p. 6082 - 6090 (2007/10/03)
Acid-catalyzed intramolecular addition of a hydroxy group to α-alkylated vinylsilanes has been studied. Treatment of (Z)-5-alkyl-5-silyl-4-penten-1-ols 1 (R = alkyl) with 5 mol % TiCl4 in CHCl3 gave trans-2-alkyl-3-silyltetrahydropyrans 2 exclusively (trans/cis = > 99/1 to 97/3). The cyclization efficiency and rate strongly depended on the geometry of the C-C double bond and the silyl group. The use of (E)-vinylsilanes resulted in lower yields with poor cis-selectivity. In the cyclization of (Z)-1 (R = Bu), the silyl group used, the reaction time, and the yield of 2 were as follows: SiMe2Ph, 9.5 h, 75%; SiMe3, 7.5 h, 66%; SiMePh2, 24 h, 58%; SiMe2-t-Bu, 0.75 h, 85%; SiMe2Bn, 1.5 h, 78%. This 1,2-silyl-migrative cyclization could be applied to stereoselective synthesis of trisubstituted tetrahydropyrans. The acid-catalyzed reaction of 1-, 2-, or 3-substituted (Z)-5-silyl-4-nonen-1-ols 8 gave r-2,t-3,c-6-, r-2,t-3,t-5-, or r-2,t-3,c-4-trisubstituted tetrahydropyrans with high diastereo-selectivity, respectively. (Z)-4-Alkyl-4-silyl-3-buten-1-ols 5 as well as 1 underwent the 1,2-silylmigrative cyclization to give 2-alkyl-3-silyltetrahydrofurans 6 with high trans-selectivity. This silicon-directed cyclization was also available for the stereoselective synthesis of tri- and tetrasubstituted tetrahydrofurans.
Acid-catalyzed cyclization of vinylsilanes bearing a hydroxy group: A new method for stereoselective synthesis of disubstituted tetrahydrofurans
Miura,Okajima,Hondo,Nakagawa,Takahashi,Hosomi
, p. 11348 - 11357 (2007/10/03)
In the presence of a catalytic amount of TsOH or TiCl4, (Z)-5-silyl-4-penten-1-ols ((Z)-1) are smoothly cyclized to 2-silylmethyl-substituted tetrahydrofurans. This cyclization is applicable to the construction of a tetrahydropyran ring. The silyl group and the geometry of the C-C double bond strongly influence the cychzation rate. TBDMS and benzyldimethylsilyl groups considerably accelerate the cyclization in comparison with a dimethylphenylsilyl group, and (E)-vinylsilanes show much lower reactivity than the corresponding (Z)-isomers. The cyclization proceeds by stereospecific syn addition of the hydroxy group. Vinylsilanes 17, 19, and 21, (Z)-5-silyl-4-penten-1-ols bearing a substituent on the methylene tether, smoothly undergo the acid-catalyzed cyclization to give trans-2,5-, cis-2,4-, and trans-2,3-disubstituted tetrahydrofurans, respectively, with moderate to high stereoselectivity. The silyl group of some cychzed products can be easily converted into a hydroxy group with stereochemical retention.
