Synthesis and Azidolysis of 2-Chlorotetramethylguanidine. Synthetic Utility of Hexa- and Tetramethylguanidinium Azide

An Asymmetric Synthesis of l-Pyrrolysine

“…11 Accordingly, the Josiphos catalyst gave rise to the 1,4-addition of methyl Grignard to α,β-unsaturated thioester 4 (Scheme 2). Attempts to functionalize the α-position with an electrophilic azide source or by an asymmetric α-halogenation 12 and subsequent nucleophilic displacement with an azide 13 did not afford the desired products. A more significant drawback of this approach was our observation that the most robust α-halogenation methods 14 were incompatible with the thioester required for the Josiphos-catalyzed reaction.…”

Stereospecific cleavage of carbon‐phosphorus bonds: Stereochemical course of the phosphinoyl curtius (harger) reaction

“…n-Butyllithium was titrated according to the method of Gilman and Schulze. 35a Grignard reagents were titrated according to the method of Gilman et al 35b 1-Phenylethylmagnesium chloride 36 and tetramethylguanidium azid 37 were prepared by literature methods. All reactions were run under nitrogen, except those which contained water or thionyl chloride, which were performed in air.…”

Guanidines in Organic Synthesis

“…The guanidinium salts shown in On the other hand, Papa reported that TMGA (28) could work as 1,3-dipolarophile in the tetrazole synthesis [104]. 5-Phenyltetrazole is quantitatively given by heating benzonitrile with 28 at 125 C for six hours without solvent (Scheme 4.42).…”