Protection-deprotection processes

In many cases, the electrochemical technique recently developed has been shown to be a fruitful alternative to chemical deprotection. Thus, organic chemistry functions that are mainly involved in protection/deprotection processes are mostly aldehydes and ketones, amines, alcohols, and thiols carboxylic acids can also be quoted, although their esterification as well as their ester hydrolyses are not straightforward. 

Nature created multienzymatic systems to accomplish extremely efficient one-pot tandem catalysis. As in an assembly line, tens of enzymes are well organised to transform simple materials to complex molecules with perfect control of selectivity hy a series of coupled reactions in the cell. It has long been chemists endeavor to extend such coordinated catalytic action to artificial processes to make synthetic chemistry more sustainable. Nowadays, owing to the resource-intensive nature of the current synthetic industry, the development of tandem one-pot reactions, avoiding the use of costly and time-consuming protection-deprotection processes as well as purification procedures of intermediates, has become especially important and valuable because society is confronted with bottle-neck problems such as energy and time shortage and environmental pollution. 

Reduce Derivatives Unnecessary derivatization - use of blocking groups, protection/ deprotection, and temporary modification of physical/chemical processes - should be minimized or avoided if possible, because such steps require additional reagents and can generate waste. 

Unnecessary derivatization (blocking group, protection/deprotection, temporary modification of physical/chemical processes) should be avoided whenever possible. 

On occasion such reductive deprotection processes can be quite selective. Electrochemical reduction of A,A -di-p-toluenesulfonyl-A-t-butoxycarbonyl derivatives of aliphatic and aromatic diamines selectively removed the p-toluenesulfonyl group attached to a primary amine site63. Yields on the mono-protected products are fair to high selective deprotection of the corresponding A,A -dibenzoyl derivatives occurred in yields >92%. 

The coupling and protection-deprotection reactions to yield Taxol were fully licensed by BMS from FSU as part of the original licensing agreement (Scheme 7.3). This so-called metal alkoxide process was patented by Holton in 1992 [13]. 

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