Iodine–alumina as an efficient and useful catalyst for the regeneration of carbonyl functionality from the corresponding 1,3-oxathiolanes and 1,3-dithiolanes in aqueous system
摘要:
A simple and useful method has been demonstrated for the deprotection of 1,3-oxathiolanes and 1,3-dithiolanes to the corresponding carbonyl compounds in excellent yield by employing catalytic amount (30 mol %) of iodine supported on neutral alumina in ethanol-water or water. The major advantages of this protocol are mild reaction conditions, less reaction time, easy to handle, high yields, inexpensive reagent and environmentally benign. (C) 2010 Elsevier Ltd. All rights reserved.
LiBF<sub>4</sub> Catalyzed Chemoselective Conversion of Aldehydes to 1,3-Oxathiolanes and 1,3-Dithianes
作者:J. S. Yadav、B. V. S. Reddy、Sushil Kumar Pandey
DOI:10.1055/s-2001-10780
日期:——
Lithium tetrafluoroborate is found to be an efficient catalyst for the chemoselective protection of both aromatic and aliphatic aldehydes as 1,3-oxathiolanes and 1,3-dithianes under mild reaction conditions. Due to the neutral reaction conditions, this method is compatible with acid sensitive substrates.
Selective desulfurization of 2-alkyl-1,3-dithianes, -oxathiolanes, or -thiazolidines 1 with one equivalent of tri-n-butyltin hydride yields acyclic compounds R1R2CHX(CH2)nSSnBu3 (X = S,O,NH; n= 2,3), (2) which can be destannylated to the corresponding mercaptans 3.
用一当量的氢化三正丁基锡对2-烷基-1,3-二硫杂环丁烷,-氧杂硫杂环戊烷或-噻唑烷1进行选择性脱硫,得到无环化合物R 1 R 2 CHX(CH 2)n SSnBu 3(X = S, O,NH; n = 2,3),(2),其可被脱甲锡化为相应的硫醇3。
Eco-friendly and Highly Chemoselective 1,3-Oxathio- and 1,3-Dithioacetalization of Aldehydes Using Ionic Liquids
作者:J. S. Yadav、B. V. S. Reddy、G. Kondaji
DOI:10.1246/cl.2003.672
日期:2003.8
Room temperature ionic liquids have been employed for the first time as novel and recyclable reaction media for the chemoselective conversion of aldehydes into their corresponding 1,3-oxathio- and dithioacetal derivatives in excellent yields under mild and neutral conditions. A wide range of functional and protecting groups such as TBDMS, PMB, THP, MOM, benzyl, propargyl ethers, acetonides, carbamates and esters are survived under these reaction conditions. The recovered activated ionic liquids can be recycled for four to five subsequent runs with consistency in activity.
Montmorillonite K-10 Clay as an Efficient Solid Catalyst for Chemoselective Protection of Carbonyl Compounds as Oxathiolanes with 2-Mercaptoethanol
作者:Nabin C. Barua、Siddhartha Gogoi、Jagat C. Borah
DOI:10.1055/s-2004-829054
日期:——
Montmorillonite K-10 clay has been found to be a mild and efficient solidcatalyst for the protection of a variety of carbonylcompounds, such as oxathiolanes, with 2-mercaptoethanol in good to excellent yields. In addition, by using this catalyst, high chemoselective protection of aldehydes in presence of ketones has been achieved.
Blue LED-Promoted Oxathiacetalization of Aldehydes and Ketones
作者:You-Chen Liu、Daggula Mallikarjuna Reddy、Xin-An Chen、Yi-Chen Shieh、Chin-Fa Lee
DOI:10.1002/ejoc.202000218
日期:2020.5.10
A visible‐light‐promoted oxathiacetalization of aldehydes and ketones with 2‐mercaptoethanol and 3‐mercaptopropan‐1‐ol in the presence of eosin Y as catalyst is described leading to the formation of 1,3‐oxathiolanes and 1,3‐oxathianes at ambient temperature and under metal‐free conditions. The solvent is playing vital role in the protection of carbonyl compounds with mercaptoalcohol.