An expedient carbon–sulfur bond formation explored through the cellulose sulfonic acid (CSA) catalyzed dithioacetal protection of carbonyl compounds

ABSTRACT

A facile carbon–sulfur bond formation was observed through the cellulose sulfonic acid (CSA) catalyzed dithioacetal protection of carbonyl compounds. In a preliminary study, the synthesis and characterization of functionalized bio-polymer, cellulose sulphonic acid (CSA) was achieved and its catalytic knack for dithioacetal protection was studied. It was discovered that CSA is an efficient, environmentally benign, recyclable catalyst for the synthesis of 1,1-dithioacetals or 1,1-dithioketals. A diverse range of aldehydes or ketones smoothly underwent the thioacetalization either with 1,3-dithiol or 1,2-dithiol. The 1,3-dithiol protection was found favored over 1,2-dithiol in terms of yields and reaction times. Acetonitrile at room temperature provides the best results among the solvents studied. The biodegradable nature of CSA, operationally simple protocol, good to excellent yields, shorter reaction times and need of very small amount of catalyst are the salient features of the present protocol.

GRAPHICAL ABSTRACT

KEYWORDS:

• Carbon-sulfur bond
• cellulose sulfonic acid (CSA)
• dithioacetals
• biodegradable
• environmentally benign
• recyclable catalyst

Acknowledgement

The author is thankful to the Head and Professor, Department of chemistry, Institute of Science, Nagpur (India) for the fruitful discussions during the work. The athors acknowledge the characterization facility provided by BCUD, Savitribai Phule Pune University, Pune (India). The authors also acknowledge the Director, School of Chemical Sciences, Swami Ramanand Teerth Marathwada University, Nanded for their affiliation support.

Disclosure statement

No potential conflict of interest was reported by the author.