S. Kotani, M. Sakamoto, K. Osakama, M. Nakajima
SHORT COMMUNICATION
in dichloromethane (5.0 mL) at 0 °C. After stirring for 0.5 h, the
reaction was quenched with saturated aqueous NaHCO3 (5 mL)
and stirred for another 0.5 h at room temperature. After filtration
through Celite, the filtrate was extracted with EtOAc (3ϫ 10 mL),
and the combined organic layer was washed with brine (30 mL) and
dried over Na2SO4. After filtration and concentration, the obtained
crude product was purified by column chromatography (hexane/
EtOAc, 10:1) to afford product 3a.
Acknowledgments
This work was partially supported by the Ministry of Education,
Culture, Sports, Science and Technology (MEXT), Japan, through
JSPS KAKENHI grant number 25860008.
Figure 4. Proposed reaction mechanism.
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Figure 5. Cyanation of the orthoesters 7. For the preparation of 8c
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Conclusions
In conclusion, we demonstrated that sterically hindered
α-cyanoamines could effectively promote the cyanation of
acetals and orthoesters in the presence of trichlorosilyl tri-
flate to produce cyanated adducts in high yields. In ad-
dition, we detected oxocarbenium cations as intermediates
through analysis of the reaction mixtures by NMR spec-
troscopy. We are currently investigating the development of
useful reactions by using sterically congested tertiary
amines as nucleophile carriers.
Experimental Section
Typical Procedure for the Cyanation with Tertiary Amine 1d: A solu-
tion of 2.0 m trichlorosilyl triflate in dichloromethane (0.5 mL,
1.0 mmol, 2.0 equiv.) was added dropwise to a solution of 1d
(220 mg, 1.0 mmol, 2.0 equiv.) and acetal 2a (76.1 mg, 0.5 mmol)
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