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Leung, M.-k.; Chou, C.-M.; Luh, T.-Y., Science of Synthesis Knowledge Updates, (2018) 2, 401.
Boron trifluoride is a mild Lewis acid and has been used to promote condensation of ethane-1,2-dithiol and carbonyl compounds to give 1,3-dithiolanes. The reaction usually proceeds in the presence of excess ethane-1,2-dithiol. Many functional groups such as esters, amines, and furans are tolerated. Selected examples are shown in Scheme 9.[19–22] Silica gel supported boron trifluoride as well as nano silica gel supported boron trifluoride have been developed;[23] these catalysts are highly efficient, reusable, and eco-friendly. Chemoselective thioacetalization of aldehydes and ketones gives the corresponding 1,3-dithiolanes 19 (Scheme 9).
Meeeee 8 Meeeeeeee ee Meeeeeee Meeeeeeee eeee Meeeee-8,8-eeeeeee Meeeeeeeeee Meeeeeeee ee Meeee Meeeeeeeeee[88–88]
M8 | M | Meeee (%) | Mee |
---|---|---|---|
Me | M | 88e | [88] |
M | MM8 | 88 | [88] |
e Mee eeeeeee eee eee eeeeeeeeeeee, eeeee eee eeeeeeeeee [Me8M(MMe)8 (8 eeeee), MeMM (8 eee%), eeeeeee, eeeeee, 8.8 e].
M8 | M8 | Meeeeee | Meeee (%) | Mee |
---|---|---|---|---|
Me | M | eeee eeeeee eee | 88 | [88] |
Me | M | eeeeee eee | 88 | [88] |
8-M8MM8M8 | M | eeee eeeeee eee | 88 | [88] |
8-M8MM8M8 | M | eeeeee eee | 88 | [88] |
8-MeM8M8 | M | eeee eeeeee eee | 88 | [88] |
8-MeM8M8 | M | eeeeee eee | 88 | [88] |
8-MeM8M8 | M | eeee eeeeee eee | 88 | [88] |
8-MeM8M8 | M | eeeeee eee | 88 | [88] |
8,8-(MM)8M8M8 | M | eeee eeeeee eee | 88 | [88] |
8,8-(MM)8M8M8 | M | eeeeee eee | 88 | [88] |
8-M8MM8M8 | Me | eeee eeeeee eee | 88 | [88] |
8-M8MM8M8 | Me | eeeeee eee | 88 | [88] |
(MM8)8 | eeee eeeeee eee | 88 | [88] | |
(MM8)8 | eeeeee eee | 88 | [88] | |
8-MeMM8M8 | Me | eeee eeeeee eee | 88 | [88] |
8-MeMM8M8 | Me | eeeeee eee | 88 | [88] |
Meeeeeeeeeee Meeeeeeee
88% Meeeee Mee Meeeeeeee Meeee Meeeeeeeeee eee 88% Meee Meeeee Mee Meeeeeeee Meeee Meeeeeeeeee:[88]
MM8•MMe8 (8.8 eM, 8.88 e MM8) eee eeeee eeeeeeee ee e eeeeeee ee eeeeee eee ee eeee eeeeee eee (8.88 e) eee MMMe8 (8 eM). Mee eeeeeee eee eeeeeee ee ee eee 8 e. Mee eeeeeeeee eeeeeeeeee eee eeeeeeee ee eeeeee eee eeeee eeeeeee, eeeee eee eeeeeee eeeeee eeee MMMe8 eee eeeee ee ee.
8,8-Meeeeeeeeee 88; Meeeeee Meeeeeeee:[88]
M eeeeeee ee ee eeeeeeee ee eeeeee (8 eeee), eeeeee-8,8-eeeeeee (8.8 eeee), eee 88% eeeeee eee eeeeeeeee MM8 (888 ee) ee 88% eeee eeeeee eee eeeeeeeee MM8 (88 ee) eee eeeeee ee e eeeeee ee eeeeeee eeeeeeeeeee. Meeee eeeeeeeeee ee eee eeeeeeee, MMMe8 eee eeeee eee eee eeeeeee eee eeeeeeee ee eeeeeee eee eeeeeeee. Mee eeeeeeee eee eeeeeeeeeeee eee eee eeeee eeeeeee eee eeeeeeeeeeeeee (MeMM eee M8M). Mee eee eeeeeeee-eeeee eeeeeeeee, eee eeeeeee eee eeeee eeeeeeeee ee MeMM. Mee eeee eee eeeeeeee eee eeeeeeeeeeee. Mee eeeeeeee eeeee eee eeeeeeeeeeeeee (MMMe8).
References
[19] | Meeeeee, M.; Meeee, M. M.; Mee, M.-M.; Meeeeeeeeeeee, M., Mee. M. Mee. Meee., (8888), 8888. |
[20] | Meee, M.; Meee, M.; Meee, M.; Meee, M.; Meeee, M.; Mee, M.; Meee, M.; Meee, M., Meee. Meeeee. (Meeeeeeee), (8888) 88, 8888. |
[21] | Meeeeeee, M. M.; Meeeeeee, M. M., Meeee. Meee. Mee. Me., (8888) 88, 8888. |
[22] | Meeeee, M. M.; Meeeee, M.; Meeeeeeeeeee, M., Meeeeeeee, (8888) 88, 8888. |
[23] | Meeeeeeee, M. M. M.; Meeeeeee, M.; Meeeee, M., Meee. M. Meeee., (8888) 8, 88. |