化学
异丁醛
醛
艾地明
位阻效应
冷凝
路易斯酸
药物化学
有机化学
羟醛缩合
催化作用
热力学
物理
作者
Guangcheng Liu,Derek Cogan,Timothy J. Owens,Tony P. Tang,Jonathan A. Ellman
出处
期刊:ChemInform
[Wiley]
日期:1999-08-17
标识
DOI:10.1002/chin.199933095
摘要
Experimental details for the first general methods for the one-step preparation of N-tert-butanesulfinyl imines (tert-butanesulfinimines) (2) from aldehydes and ketones is described. To effect the condensations of tert-butanesulfinamide (1) with aldehydes, the Lewis acidic dehydrating agents MgSO4, CuSO4, or Ti(OEt)4 are employed. Aldehyde condensations mediated by MgSO4 proceed in high yields (84−96%) when an excess of aldehyde is used. In contrast, only a slight excess of aldehyde (1.1 equiv) relative to tert-butanesulfinamide provides sulfinimines in high yields when the more Lewis acidic dehydrating agent CuSO4 is used. The CuSO4-mediated procedure is effective for a wide range of aldehydes, including sterically demanding aldehydes, such as isobutyraldehyde (90%), and electron-rich aldehydes, such as p-anisaldehyde (81%). The still more Lewis acidic Ti(OEt)4 and Ti(O-i-Pr)4 also afford N-tert-butanesulfinyl aldimines from especially unreactive aldehydes, such as pivaldehyde (82%). In addition, Ti(OEt)...
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