Selective Alkylation of Tetraaminobiphenol Macrocyclic Ligands

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Solution Overview

Problem

Existing methods for producing tetraaminobiphenol macrocyclic ligands suffer from low yields and require multiple Mannich reactions for different substituents, with potential alkylation of phenol moieties and limited selectivity.

Innovation Solution

A process involving a high molar ratio of a compound (III) to NH sites in a precursor (II) in the presence of a base, allowing for direct alkylation of tetraaminobiphenol macrocyclic ligands, avoiding phenol alkylation and achieving high yields and selectivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If direct alkylation of tetraaminobiphenol macrocyclic ligand is performed with limited equivalents of alkylating agent, then competing reactions at phenol groups are avoided, but the yield is limited to maximum 50% due to incomplete substitution

Engineering Contradiction:

Improveselectivity of alkylationVSAvoidyield of tetracarboxyaminobiphenol ligand

Core Design Contradiction:

ReliabilityVSProductivity

Solution Approach 1:

The patent applies preliminary action by first protecting the phenol groups as silyl ethers before performing the alkylation reaction. This pre-protection prevents competing alkylation at phenol sites, allowing use of excess alkylating agent to achieve complete substitution at all four amine sites, thereby resolving the yield limitation while maintaining selectivity

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent uses silyl protecting groups as intermediary compounds that temporarily mask the phenol groups during alkylation. These intermediaries prevent unwanted side reactions, enable complete substitution, and are subsequently removed to give the final product with high yield and selectivity

Inventive Principle:

Principle #24Intermediary (Mediator)

2Adaptability or versatility

If multiple Mannich reactions are run for different substituents, then diverse tetraaminobiphenol macrocyclic ligands can be produced, but the process complexity increases and requires separate reactions for each substituent type

Engineering Contradiction:

Improvediversity of ligand substituentsVSAvoidnumber of separate reactions required

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent achieves universality by developing a general alkylation methodology that can introduce various substituents (alkyl, allyl, benzyl groups) using the same reaction framework. The unified approach using excess alkylating agent with or without phenol protection eliminates the need for separate Mannich reactions for each substituent type, reducing process complexity while maintaining versatility

Inventive Principle:

Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent applies parameter changes by varying the alkylating agent structure (different R groups) while maintaining the same reaction conditions and procedure. This allows diverse substitution patterns to be achieved through simple parameter modification rather than developing separate reaction protocols for each substituent

Inventive Principle:

Principle #35Parameter changes

3Productivity

If excess alkylating agent is used for complete substitution, then all four amine sites can be substituted, but competing alkylation of phenol groups occurs

Engineering Contradiction:

Improveyield of fully substituted ligandVSAvoidalkylation of phenol moieties

Core Design Contradiction:

ProductivityVSObject-generated harmful factors

Solution Approach 1:

The patent applies preliminary action by protecting phenol groups as silyl ethers before alkylation, preventing competing phenol alkylation and enabling use of excess alkylating agent to achieve complete substitution at all four amine sites with high yield and selectivity

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

Silyl protecting groups serve as intermediaries that temporarily block phenol sites during alkylation, allowing complete amine substitution with excess reagent while preventing harmful phenol alkylation, and are subsequently removed to give the final product

Inventive Principle:

Principle #24Intermediary (Mediator)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The process achieves high yields and selectivity in producing tetra-substituted aminobiphenol macrocyclic ligands, even without protecting phenol moieties, and allows for diverse substitution patterns.

Implementation Method 1

treating a precursor compound having the structure (II) with a compound having the structure R6-L where L represents a leaving group (hereinafter compound (III)) in the presence of a base

Methodology Applied

Scientific EffectAlkylation: Chemical Bonding

Implementation Method 2

direct alkylation of tetraaminobiphenol macrocyclic ligands

Methodology Applied

Scientific EffectNucleophilic substitution: Chemical Bonding

Data Source

PatentUS12415787B2Process for the production of tetraaminobiphenol macrocyclic ligands; and novel tetraaminobiphenol macrocyclic ligands

Publication Date: 2025.09.16 ECONIC TECH LTD

AI summary

A process for preparing a tetra-substituted aminobiphenol macrocyclic ligand having the structure (I), including the step of treating a precursor compound having the structure (II) with a compound having the structure R6-L where L is a leaving group (hereafter compound (III)) in the presence of a base.