Catalytic Allylic Chlorination of Natural Terpenic Olefins Using Supported and Nonsupported Lewis Acid Catalysts

Abstract

A mild and convenient method for the allylic chlorination of naturally occurring terpenic olefins was investigated in the presence of different supported and non-supported Lewis acid catalysts. The reaction has been tested on carvone as a model substrate in the presence of sodium hypochlorite as chlorine donor. The scope and limitations of transition metal-based Lewis acid catalysts, stoichiometry, and substrate structure were evaluated. Among the iron precursors used, FeCl3 and FeCl2 provide the promise of a general approach to allylic or vinylic chlorination reaction. Various terpenic olefins were examined in the presence of FeCl3/NaOCl combination system. The catalytic chlorination proceeds under mild conditions with short reaction time and shows a high selectivity affording the corresponding chlorides in good to excellent yields.

Chlorination of trichlorosilane/chlorodimethylsilane using metal chlorides: experimental and mechanistic investigations

“…For instance, (a) chlorination of methylphenyldichlorosilane to chlorinated methylphenyldichlorosilanes with gaseous chlorine has been catalysed by FeCl 3 , SbCl 5 , SnCl 4 and AlCl 3 ; 13 (b) chlorination of 1,3-dithiolanes and 1,3-dithianes with CH 2 Cl 2 has been catalysed by WCl 6 ; 14 and (c) chlorination of allyl groups in terpenic olefins (β-pinene and carvone) with NaClO has been catalysed by MoCl 5 , AlCl 3 , FeCl 3 and FeCl 2 . 15,16 Metal chlorides can be used not only as catalysts but also directly as chlorine sources in reactions, such as in the photochemical chlorination of methane mediated by FeCl 3 . 17 In addition, the boiling points of WCl 6 (346.7 °C) and MoCl 5 (268.0 °C) are very high and they are easily removed by distillation.…”

Selective catalytic synthesis of new terpenic chlorides using NaDCC as an eco-friendly and highly stable FAC agent

“…28 In contrast, the synthesis of allylic halides starting from allylic olens is widely reported. 29 For instance, the allyl chloride derivatives could be prepared from the corresponding allylic alcohols in presence of different reagents, e.g., titanium IV chloride, 30 thionyl chloride, 31 hydrochloric acid, 32 chlorosilanes, 33 sulfuryl chloride, 34 N-chlorosuccinimide (NCS) 35 or iridium catalyst. 36,37 However, the allylic chloride intermediates can be synthesized from aldehydes through sequences of olenation-reduction-halogenation.…”

Catalytic dehydrogenation of natural terpenes via CuPd alloy nanoparticles generated on mesoporous graphitic carbon nitride

“…[16] To date, it has been observed that the conversion reactions of terpenes are mostly conducted by using homogeneous catalysts and that the transformation reactions performed in the presence of heterogeneous catalysts are very limited. [40,41] As most of naturally occurring products, natural terpenic olefins expose some allyl, vinyl or isopropenyl groups as part of their structures for further functionalization. These groups were used repeatedly as potential reactive sites to yield new natural products or more complex structures.…”

“…These groups were used repeatedly as potential reactive sites to yield new natural products or more complex structures. [40,41] Recently, it has been reported that the catalytic dehydrogenation reaction represents a sustainable and efficient alternative to selective aromatic terpenic derivatives starting from naturally occurring terpenes such as himachalene, limonene, carvone, carveol, perillyl alcohol, and limonaketone. [16] In addition, the listed terpenes are obtained from natural essential oils of various aromatic plants, for example, the main natural sources of himachalene and limonene are Cedrus atlantica and citrus oils, respectively.…”