Table 1.

Decarbamoylation Rate Constants k₂₁ in the Absence of Carbamate at 25 °C ^a

Carbamoyl Group Substituents	Leaving Group b	Carbamate Common Name	nc	k21 × 106 min−1
N-monomethyl
	HTMA	Monomethyl neostigmine	8	12300 ± 400
	NAP		4	12500 ± 200
	1-Napthol	carbaryl	7	11300 ± 600
	M7H		10	12900 ± 500
N,N-dimethyl
	HTMA	neostigmine	15	3600 ± 300
	M7H		6	3000 ± 300
	F		4	3200 ± 200
N-ethyl-N-methyl
	HTMA		16	150 ± 20
	NAP	rivastigmine	19	160 ± 10
	M7H		4	200 ± 40
N,N-diethyl
	HTMA		11	16 ± 5
	NAP		4	23 ± 6
	M7H		9	14 ± 4
	F		2	7 ± 1

^aValues of k₂₁ obtained with the second protocol described in the Experimental Procedures, as illustrated in Figure 3.

^bLeaving group structures are shown in Figure 1.

^cNumber of independent measurements.