Synthesis 2015; 47(10): 1379-1386
DOI: 10.1055/s-0034-1380168
short review
© Georg Thieme Verlag Stuttgart · New York

Zinc Tetrafluoroborate: A Versatile and Robust Catalyst for Various­ Organic Reactions and Transformations

Anirban Sarkar
Department of Chemistry, Visva-Bharati (A Central University), Santiniketan 731235, India   Email: adinath.majee@visva-bharati.ac.in
,
Sougata Santra
Department of Chemistry, Visva-Bharati (A Central University), Santiniketan 731235, India   Email: adinath.majee@visva-bharati.ac.in
,
Shrishnu Kumar Kundu
Department of Chemistry, Visva-Bharati (A Central University), Santiniketan 731235, India   Email: adinath.majee@visva-bharati.ac.in
,
Nirnita Chakraborty Ghosal
Department of Chemistry, Visva-Bharati (A Central University), Santiniketan 731235, India   Email: adinath.majee@visva-bharati.ac.in
,
Alakananda Hajra
Department of Chemistry, Visva-Bharati (A Central University), Santiniketan 731235, India   Email: adinath.majee@visva-bharati.ac.in
,
Adinath Majee*
Department of Chemistry, Visva-Bharati (A Central University), Santiniketan 731235, India   Email: adinath.majee@visva-bharati.ac.in
› Author Affiliations
Further Information

Publication History

Received: 02 November 2014

Accepted after revision: 09 January 2015

Publication Date:
17 February 2015 (online)


Abstract

This account discusses the use of aqueous zinc(II) tetrafluoroborate as a mild and selective catalyst for various important organic transformations. In general, the advantages of the methodologies discussed include high yields; short reaction times; excellent regio-, chemo­-, and stereoselectivities; mild reaction conditions; and high efficiency. The use of the catalyst in a synthesis of the antihypertensive drug metoprolol is also discussed.

1 Introduction

2 Protection and Deprotection

2.1 Selective Deprotection of tert-Butyl(dimethyl)silyl Ethers

2.1 Tetrahydropyranylation and Depyranylation of Alcohols

2.2 Conversion of Aldehydes into Geminal Diacetates or Cyanoacetates

2.3 Selective Thioacetalization of Aldehydes

2.4 Mild and Efficient Cleavage of Oximes, Hydrazones, and Semicarbazones

3 Rearrangements of Ten-Membered-Ring Allenes

4 Organic Methodologies

4.1 Mannich Reaction of Aldimines with Silyl Enol Ethers in Aqueous Media

4.2 Synthesis of Highly Substituted Pyrroles under Solvent-Free Conditions

4.3 One-Pot Biginelli Reaction at Room Temperature

4.4 Epoxide Ring Opening with Amines and Synthesis of Metoprolol

5 Conclusions