# Nankai University chemists convert tetrasubstituted alkenes into fused δ-lactams with an Ir(III) catalyst

- Published: 2026-11-05 21:21 UTC
- Section: Science › Chemistry
- Tags: nitrene transfer, Ir(III) catalysis, tetrasubstituted alkenes, fused δ-lactams, aza-semipinacol rearrangement, aziridination, azacarbocation, diastereoselectivity, Nankai University, Nature Communications
- URL: https://realtech.media/news/rt-fd43256f0067c0a203e6db23_nankai_university_chemists/

**A group at Nankai University reported an Ir(III)-catalyzed nitrene-transfer cascade that turns congested tetrasubstituted alkenes into cycloalkane-fused δ-lactams under mild conditions.**

![Nankai University chemists convert tetrasubstituted alkenes into fused δ-lactams with an Ir(III) catalyst](https://sgzwpqqelzmajkcubgkl.supabase.co/storage/v1/object/public/rt-media/2026/11/f5ae44cdabeec7df.jpg)
*Bing-lab, Wikimedia Commons, CC BY-SA 4.0*

Researchers at the State Key Laboratory and Institute of Elemento-Organic Chemistry, Nankai University (Tianjin, China), have described a way to convert sterically congested tetrasubstituted alkenes into cycloalkane-fused δ-lactams. The work was published on 4 November 2026 in Nature Communications; the corresponding author is Hao Wang. [1]

Transition-metal-catalyzed nitrene transfer is an established strategy for alkene functionalization. According to the authors, its use on tetrasubstituted alkenes has remained severely underdeveloped. [1]

## Ir(III)-catalyzed cascade

The team reports an Ir(III)-catalyzed aziridination–rearrangement cascade triggered by a nitrene. It converts cyclic-substituted tetrasubstituted alkenes into cycloalkane-fused δ-lactams. [1]

The reaction runs under mild conditions. The authors report excellent yields and uniformly high diastereoselectivities. [1]

The method is compatible with carbon-, oxygen- and nitrogen-based nucleophiles. According to the authors, the substrates include structurally complex and biologically relevant ones. [1]

## Mechanism: aziridination and aza-semipinacol rearrangement

Experimental and computational studies, the authors say, support the following sequence. An Ir–nitrenoid performs a concerted aziridination of the alkene and generates a strained tricyclic intermediate. [1]

This intermediate then undergoes an aza-semipinacol rearrangement driven by strain release. The rearrangement gives a bicyclic azacarbocation. [1]

The azacarbocation can be intercepted by a nucleophile or can undergo elimination. These two routes lead to structurally diverse fused δ-lactam architectures, and the authors describe the access as rapid. [1]

The authors present the result as a nitrene-triggered carbocationic rearrangement manifold for functionalizing tetrasubstituted alkenes. They state that it expands the synthetic potential of transition-metal-catalyzed nitrene transfer. [1]

The study is a synthetic-chemistry method developed in the laboratory. The material does not describe applications of the products.

## Sources

1. [Nature Communications](https://doi.org/10.1038/s41467-026-79231-z)

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Source: RealTech, realtech.media — https://realtech.media/news/rt-fd43256f0067c0a203e6db23_nankai_university_chemists/