Halomethoxylation of monoterpenes using (dichloroiodo)benzene

Abstract

Reactions of (dichloroiodo)benzene or (dichloroiodo)benzene/iodine with various monoterpenes in methanol provide a selective approach to the respective products of chloromethoxylation or iodomethoxylation of the double bond. The halomethoxylation of (+)-3-carene, carvone, and β-pinene proceeds with especially high regio-and stereoselectivity affording an appropriate single product in each case, while the reaction of limonene gives products of functionalization of both double bonds. This new methodology for the controlled introduction of halogen substituents into the structure of naturally occuring monoterpenes provides an entry into various potentially important synthetic intermediates.

Advances in Synthetic Applications of Hypervalent Iodine Compounds

“…This is a fast reaction giving products of gem- dichlorination in good yields. (Dichloroiodo)­benzene reacts with monoterpenes in methanol via the ionic pathway, giving products of chloromethoxylation with excellent regio- and stereoselectivity …”

“…(Dichloroiodo)benzene reacts with monoterpenes in methanol via the ionic pathway, giving products of chloromethoxylation with excellent regio-and stereoselectivity. 271 Nicolaou and co-workers reported enantioselective 1,2dichlorination of allylic alcohols using (dichloroiodo)arenes in the presence of catalytic amounts of a dimeric cinchona alkaloid derivative (DHQ) 2 PHAL 115 as chiral auxiliary. 272 For example, the (DHQ) 2 PHAL 115-catalyzed enantioselective dichlorination reaction of trans-cinnamyl alcohols 116 with 4-Ph(C 6 H 4 )ICl 2 affords products 117 in good yields and enantioselectivities (Scheme 36).…”

Enzymatic halogenation of the phenolic monoterpenes thymol and carvacrol with chloroperoxidase

“…The controlled introduction of halogen substituents into the structure of naturally occurring monoterpenes provides an entry into numerous important synthetic intermediates. 4 Halogenated secondary metabolites are common in marine plants (i.e. seaweeds), while they are rare in land plants, due to the abundance of chloride and bromide ions in seawater.…”

Recyclable Hypervalent Iodine Reagents in Modern Organic Synthesis

“…The recovered product was re-oxidized back to the respective reagent by reaction with m -chloroperbenzoic acid ( m -CPBA). Certain non-polymeric HVI(III) reagents such as 86 – 89 , biphenyl-based HVI(III) reagents 90 – 93 , as well as terphenyl-based HVI(III) reagents 94 and 95 have also been synthesized; 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 their reactivity patterns have already been discussed in previous reviews. 1b 6 7 The structures of these non-polymeric recyclable HVI(III) reagents are shown in Figure 6 .…”