1214-35-3

Upstream product

• 312326-14-0 N-benzyl-N-(cyclohex-1-enyl)-2-iodoacetamide 
• 4471-09-4 N-benzylcyclohexylimine 
• 108-94-1 cyclohexanone 
• 312326-12-8 N-benzyl-2-bromo-N-(cyclohex-1-en-1-yl)acetamide 
• 32495-49-1 N-benzyl-2-chloro-N-(cyclohex-1-en-1-yl)acetamide 
• 497968-26-0 N-benzyl-2-(2-oxo-cyclohexyl)acetamide 
• 100-46-9 benzylamine 

Relevant academic research and scientific papers

Tin-free visible light photoredox catalysed cyclisation of enamides as a mild procedure for the synthesis of γ-lactams

The first visible light mediated tin-free cyclisation of α-chloroenamides leading to the synthesis of substituted γ-lactams with excellent stereoselectivity is reported. The protocol employs the single-electron reduction of activated C-Cl bonds, which are typically inert towards reduction.

How do analogous α-chloroenamides and α-iodoenamides give different product distributions in 5-Endo radical cyclizations?

5-Endo cyclizations of N-alkenyl carbamoylmethyl radicals provide γ-lactam radicals, which in turn evolve to reduced or non-reduced (alkene) products depending on reagents and reaction conditions. Several groups have made surprising observations that chlorides are better radical precursors than iodides in such cyclizations. Here is described a detailed study of tin and silicon hydride-mediated radical cyclizations of N-benzyl-2-halo-N-cyclohex-1- enylacetamides. The ratios of directly reduced, cyclized/reduced, and cyclized/non-reduced products depend not only on the reaction conditions and reducing reagent but also on the precursor. Prior explanations for the precursor-dependent product ratios based on amide rotamer effects are ruled out. The precursor-dependent behavior is further dissected into two different effects: (1) the ratio of cyclized/reduced products to cyclized/non-reduced products depends on the ability of the radical precursor to react with the product γ-lactam radical in competition with tin hydride (iodides can compete, chlorides cannot), and (2) the occurrence of large amounts of directly reduced (noncyclized) products in the case of iodides is attributed to a competing ionic chain reaction by which the precursor is reductively deiodinated with HI. This side reaction is not available to chlorides, thereby explaining why the chlorides are better precursors in such reactions. The ability of the iodides to provide cyclized products can be largely restored by adding base. The chlorides and iodides then become complementary precursors, with chlorides giving largely cyclized/reduced products and iodides giving largely cyclized/non-reduced products.

Oxidative radical cyclization on enamide systems using n-Bu3SnH and dilauroyl peroxide

Efficient 5-endo and 6-endo oxidative radical cyclizations on enamide systems are described using nBu3SnH and dilauroyl peroxide both as initiator and oxidant. Dibenzoyl peroxide and dicumyl peroxide were also tested in the same reaction and the product yields were very similar to those obtained with dilauroyl peroxide. The erythrina ring system was constructed in a two-step sequence featuring this novel process.

Is an iodine atom almighty as a leaving group for Bu3SnH-mediated radical cyclization? The effect of a halogen atom on the 5-endo-trig radical cyclization of N-vinyl-α-halo amides

The effect of a halogen atom as a leaving group on Bu3SnH-mediated 5-endo-trig radical cyclization of N-(cyclohex-1-enyl) α-halo amides was examined. The cyclization of α-chloro amides occurred with a high degree of efficiency, whereas the corresponding α-iodo congeners gave only limited quantities of cyclization products. A detailed study revealed that these phenomena could be attributed to the initial conformations of α-halo amides. The cyclizing ability of α-iodo amides can be restored with Bu3SnCl or Bu3SnF as an additive. The cyclization of an α-iodo amide in the presence of Bu3SnF could be applied to a short-step synthesis of lycoranes featuring sequential 5-endo-trig and 6-endo-trig radical cyclizations.

The use of an iodine atom as a leaving group for Bu3SnH-mediated 5-endo-trig radical cyclization of α-halo amides is not recommended

Bu3SnH-mediated 5-endo-trig radical cyclization of N-(cyclohex-1-enyl) α-chloro amides occurred with a high degree of efficiency, whereas the corresponding α-iodo congeners gave only limited quantities of the cyclization products. The cyclizing