Intramolecular reactions in which two reactive moieties are connected through removable tethers are attractive strategy in organic synthesis, because higher reactivity and selectivity than the corresponding intermolecular reaction are expected.
**Intramolecular Bis-Silylation
Intramolecular silylations with the tethered silicon atom was particularly attractive. We actually found that intramolecular variants of bis-silylations exhibited high reactivities, higher stereoselectivities, and higher applicability to organic synthesis. Through stereoselective intramolecular bis-silylation of homoallylic alcohols, we made stereoselective total synthesis of (–)-Avenaciolide [Ref. 1]. We also established a synthetic access to highly enantioenriched allylsilanes by intramolecular bis-silylation of allylic alcohols through highly efficient chirality transfer [Ref. 2]. In a similar manner, enantioenriched allenylsilanes are synthesized from enantienriched propargyl alcohols [Ref. 3].
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**Intramolecular Cyanoboration
We have also developed intramolecular borylations [Ref. 4]. Intramolecular cyanoboration, for instance, proceeded with high regio- and stereoselectivity than the corresponding intermolecular cyanoboration. Highly substituted a,b-unsaturated nitriles were prepared from the cyanoboration products.
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**Related Researches
-Transmetallative Cyclizative Carboboration
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**References
-Ref. 1
--Diastereoselective Intramolecular Bis-Silylation of a Carbon-Carbon Double Bond. A Highly Stereocontrolled Synthesis of (-)-Avenaciolide. M. Suginome, Y. Yamamoto, K. Fujii, Y. Ito, '''J. Am. Chem. Soc.''' ''1995'', 117, 9608–9609, [[10.1021/ja00142a047>http://dx.doi.org/10.1021/ja00142a047]]
-Ref. 2
--New Synthesis of (E)-Allylsilanes with High Enantiopurity via Diastereoselective Intramolecular Bis-Silylation of Chiral Allylic Alcohols M. Suginome, A. Matsumoto, Y. Ito, '''J. Am. Chem. Soc.''' ''1996'', 118, 3061–3062, [[10.1021/ja954251x>http://dx.doi.org/10.1021/ja954251x]]
--Synthesis of Highly Enantio-enriched Allylsilanes via Palladium-catalyzed Intramolecular Bis-Silylation. Determination of the Enantiomeric Excesses through Regio- and Stereoselective Hydroboration with 9-BBN M. Suginome, T. Iwanami, A. Matsumoto, Y. Ito, '''Tetrahedron: Asymmetry''', ''1997'', 8, 859-862, [[10.1016/S0957-4166(97)00073-6>http://dx.doi.org/10.1016/S0957-4166(97)00073-6]]
--Stereoselective Cyclization of Highly Enantio-Enriched Allylsilanes with Aldehydes via Acetal Formation: New Asymmetric Access to Tetrahydropyrans and Piperidines M. Suginome, T. Iwanami, Y. Ito, '''J. Org. Chem'''. ''1998'', 63, 6096-6097, [[10.1021/jo981173y>http://dx.doi.org/10.1021/jo981173y]]
--Asymmetric Synthesis of 2,3-Disubstituted Oxepanes via Acetalization-Cyclization of an Enantioenriched Functionalized Allylsilane with Aldehydes M. Suginome, T. Iwanami, Y. Ito, '''Chem. Commun'''. ''1999'', 2537-2538, [[10.1039/a908603j>http://dx.doi.org/10.1039/a908603j]]
--Asymmetric Synthesis of Cyclic Alkenes via Cyclization of Enantioenriched Allylsilanes M. Suginome, T. Iwanami, A. Yamamoto, and Y. Ito, '''Synlett''', ''2001'', 1042-1045, [[10.1055/s-2001-14656>http://dx.doi.org/10.1055/s-2001-14656]]
--Solid-Phase Synthesis and Asymmetric Reactions of Polymer-Supported Highly Enantioenriched Allylsilanes M. Suginome, T. Iwanami, and Y. Ito, '''J. Am. Chem. Soc.''' ''2001'', 123, 4356-4357, [[10.1021/ja005865r>http://dx.doi.org/10.1021/ja005865r]]
--Stereoselective Synthesis of Highly Enantioenriched (E)-Allylsilanes by Palladium-Catalyzed Intramolecular Bis-Silylation: 1,3-Chirality Transfer and Enantienrichment via Dimer Formation M. Suginome, T. Iwanami, Y. Ohmori, A. Matsumoto, Y. Ito, '''Chem. Eur. J.''', ''2005'', 11, 2954-2965, [[10.1002/chem.200401031>http://dx.doi.org/10.1002/chem.200401031]]
-Ref. 3
--Palladium-Catalyzed Intramolecular Bis–Silylation of Propargylic Alcohols: A New Stereospecific Access to Chiral Allenylsilanes M. Suginome, A. Matsumoto, Y. Ito, '''J. Org. Chem.''' ''1996'', 61, 4884-4885, [[10.1021/jo960778w>http://dx.doi.org/10.1021/jo960778w]]
-Ref. 4
--Palladium- and Nickel-Catalyzed Intramolecular Cyanoboration of Alkynes M. Suginome, A. Yamamoto, M. Murakami, '''J. Am. Chem. Soc.''' ''2003'', 125, 6358-6359, [[10.1021/ja0349195>http://dx.doi.org/10.1021/ja0349195]]
--Synthetic Application of Intramolecular Cyanoboration on the Basis of Removal and Conversion of a Tethering Group by Palladium-Catalyzed Retro-allylation T. Ohmura, T. Awano, M. Suginome, H. Yorimitsu, K. Oshima, '''Synlett''' ''2008'', 423-427, [[10.1055/s-2008-1032075>http://dx.doi.org/10.1055/s-2008-1032075]]
