Abstract
The Morita-Baylis-Hillman (MBH) reaction is an important method for forming carboncarbon bonds between carbonyl-containing compounds and activated olefins. However, the slow reaction rate with electron-rich electrophilic partners has limited its wider use. To overcome this drawback, the effects of pyridinium-based ionic liquids mediated quinuclidine catalytic system for MBH reactions were studied. The method is simple, involving neat and open-flask conditions, and is compatible with a wide range of reagents. We offered general pyridinium-based ionic liquids-mediated quinuclidine catalysis mechanism that is responsible for the observed rate increase. The synthetic versatility of the MBH adducts is demonstrated by the synthesis of important building blocks for the natural product (-)-sitophilure. The authors anticipate that this pyridinium-based ionic liquids-mediated quinuclidine protocol could serve as a general methodology for the MBH reaction. In summary, the study presents a simple and effective method to enhance the reaction rate of the MBH reaction. The authors believe this method has the potential for broader applications and may contribute to developing new synthetic strategies for organic synthesis. We successfully recycled the catalytic system up to 7 runs without losing any catalytic activity.
Graphical Abstract
[http://dx.doi.org/10.1021/ja0717865] [PMID: 18041831]
[http://dx.doi.org/10.1002/ejoc.202101448]
[http://dx.doi.org/10.1039/C8NJ02483A]
[http://dx.doi.org/10.1016/bs.aihch.2018.09.003]
[http://dx.doi.org/10.1021/cr010043d] [PMID: 12630854]
[http://dx.doi.org/10.1021/acs.jmedchem.1c01940] [PMID: 35427109]
[http://dx.doi.org/10.2174/9781681085647118080008]
[http://dx.doi.org/10.2174/1385272819666141125003114]
[http://dx.doi.org/10.2174/157017808784872052]
[http://dx.doi.org/10.2174/157017941206150828114416]
[http://dx.doi.org/10.1155/2018/5758076] [PMID: 30410798]
[http://dx.doi.org/10.3390/molecules14103989] [PMID: 19924044]
[http://dx.doi.org/10.1021/jo0348470] [PMID: 12968914]
[http://dx.doi.org/10.1021/jo020199t] [PMID: 12153281]
[http://dx.doi.org/10.1039/C5RA10499H]
[http://dx.doi.org/10.1007/s10593-020-02636-1]
[http://dx.doi.org/10.1039/a907754e]
[http://dx.doi.org/10.1055/s-0030-1259683]
[http://dx.doi.org/10.1002/chem.201604616] [PMID: 27775188]
[http://dx.doi.org/10.4236/jbise.2009.25047]
[http://dx.doi.org/10.1016/j.crgsc.2021.100069]
[http://dx.doi.org/10.1021/jacs.5b01352] [PMID: 25773275]
[http://dx.doi.org/10.1016/j.molstruc.2022.133133]
[http://dx.doi.org/10.1039/a907119i]
[http://dx.doi.org/10.1021/ja410781z] [PMID: 24354494]
[http://dx.doi.org/10.1002/ejoc.200700030]
[http://dx.doi.org/10.1021/jacs.9b03679] [PMID: 31140796]
[http://dx.doi.org/10.1007/s10562-019-02773-z]
[http://dx.doi.org/10.1039/C6RA03660K]
[http://dx.doi.org/10.1007/s10562-014-1392-4]
[http://dx.doi.org/10.1007/s10563-021-09325-9]
[http://dx.doi.org/10.2174/157017912798889116]
[http://dx.doi.org/10.2174/1385272820666160527101844]
[http://dx.doi.org/10.2174/138527211795703630]
[http://dx.doi.org/10.2174/9781681085746118020012]
[http://dx.doi.org/10.2174/157017907782408806]
[http://dx.doi.org/10.2174/1877944111101020166]
[http://dx.doi.org/10.2174/1570193X13666151125230810]
[http://dx.doi.org/10.1002/jhet.5570430601]
[http://dx.doi.org/10.1016/j.tet.2005.10.048]
[http://dx.doi.org/10.1021/jo048391d] [PMID: 15760226]
[http://dx.doi.org/10.3389/fchem.2019.00625] [PMID: 31620423]
[http://dx.doi.org/10.1021/jp203433u] [PMID: 21942824]
[http://dx.doi.org/10.1007/s11696-020-01135-z]
[http://dx.doi.org/10.1021/acs.energyfuels.0c00426]
[http://dx.doi.org/10.3390/molecules27092940] [PMID: 35566291]
[http://dx.doi.org/10.1016/j.molliq.2021.118160]
[http://dx.doi.org/10.1016/S0022-474X(01)00027-3]
[http://dx.doi.org/10.1080/09670874.2022.2124324]
[http://dx.doi.org/10.1139/v08-032]
[http://dx.doi.org/10.1590/S0103-50531999000500005]
[http://dx.doi.org/10.1016/S0957-4166(96)00455-7]
[http://dx.doi.org/10.1016/S0040-4039(00)61147-4]
[http://dx.doi.org/10.3390/insects12060532] [PMID: 34200992]
[http://dx.doi.org/10.1111/1750-3841.13931] [PMID: 29030875]
[http://dx.doi.org/10.3390/biology11091295] [PMID: 36138774]
[http://dx.doi.org/10.1021/ol991198z] [PMID: 10814245]