through a gem-dichloroepoxide intermediate. However, Link disclosed a Bargellini-type reaction in an 1894 patent application, and hence, might have been the first to report a method involving a gem-dichloroepoxide.3a Wilkins Reeve conducted extensive mechanistic investigations on the original reaction reported by Jocic as well as new conversions of trichloromethyl carbinols into 2-substituted carboxylic acids and heterocycles between 1960-1980.5,8,9 Although Corey and Link are duly credited with the preparation of .-amino acids from trichloromethyl carbinols (the Corey-Link reaction, vide infra), Reeve appears to be the first to prepare .-amino acids in a Jocic-type process, although his syntheses were racemic.9 Researchers have expanded Jocic- Reeve reactions considerably in scope and breadth since Reeve’s pioneering investigations. Advances and applications since 2001 are the focus of this section.
In 2004, Blanchet and Zhu reported the preparation of several substituted 2-imino-4- thiazolidinones (10) by way of the Jocic-Reeve reaction (Scheme 2).10 The authors significantly improved upon Reeve’s reported yield for the synthesis of 2-imino-5-phenylthiazolidin-4-one8d after conducting an extensive survey of bases and solvents. Optimal conditions required treatment of 2,2,2-trichloro-1-phenylethanol with thiourea using four equivalents of NaOH in DME-H2O. The secondary trichloromethyl carbinols (unlike tertiary trichloromethyl carbinols, vide supra) did not react appreciably when treated with DBU in methyl alcohol or when introduced to base in aprotic media. The authors also established a one-pot conversion of aldehydes to 10, albeit in lower yields relative to the two-step approach.
Scheme 2. Preparation of 2-imino-4-thiazolidinones (10) by a Jocic-Reeve reaction.
Stick and coworkers surveyed the reactions of five nucleophiles with trichloromethyl-.-D- allofuranose derivative 11 in methyl alcohol using DBU, rather than hydroxide, as the base.11 These modified Jocic-Reeve reaction conditions, analogous to those introduced by Dominguez in the so-called modified Corey-Link reaction,4b produced several interesting .-substituted methyl esters 12 in moderate to high yields (Table 1). Notably, fluoride product 12b was prepared in high yield using CsF as a nucleophile source. Such conditions proved superior to those employed by Oliver and coworkers in their earlier preparations of .-fluorocarboxylic acids by Jocic-Reeve reactions,12 although Oliver surveyed less compliant disubstituted trichloromethyl carbinols
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