753-89-9Relevant articles and documents
Stephenson et al.
, p. 4184,4187 (1972)
Formamides as Lewis Base Catalysts in SNReactions—Efficient Transformation of Alcohols into Chlorides, Amines, and Ethers
Huy, Peter H.,Motsch, Sebastian,Kappler, Sarah M.
supporting information, p. 10145 - 10149 (2016/08/16)
A simple formamide catalyst facilitates the efficient transformation of alcohols into alkyl chlorides with benzoyl chloride as the sole reagent. These nucleophilic substitutions proceed through iminium-activated alcohols as intermediates. The novel method, which can be even performed under solvent-free conditions, is distinguished by an excellent functional group tolerance, scalability (>100 g) and waste-balance (E-factor down to 2). Chiral substrates are converted with excellent levels of stereochemical inversion (99 %→≥95 % ee). In a practical one-pot procedure, the primary formed chlorides can be further transformed into amines, azides, ethers, sulfides, and nitriles. The value of the method was demonstrated in straightforward syntheses of the drugs rac-Clopidogrel and S-Fendiline.
Kinetics of the gas-phase elimination reaction of benzyl chloroformate and neopentyl chloroformate
Lezama, Jesus,Domnguez, Rosa M.,Chuchani, Gabriel
, p. 104 - 112 (2015/04/22)
The gas-phase eliminations of benzyl chloroformate (475-523 K, 31-103 Torr) and neopentyl chloroformate (563-622 K, 37-70 Torr), in a deactivated static reaction vessel, and in the presence of a free radical suppressor, are homogeneous, unimolecular, and follow a first-order rate law. The rate coefficients are expressed by the following Arrhenius equations: Benzyl chloroformate log κI = (13.30 ± 0.38) - (152.9 ± 3.6) kJ mol-1(2.303RT)-1; r = 0.9989 Neopentyl chloroformate Formation of neopentyl chloride: log κI = (14.29 ± 0.48) - (196.3 ± 5.5) kJ mol-1(2.303RT)-1; r = 0.9986 Formation of 2-methylbutenes: log κII = (12.12 ± 0.73) - (178.2 ± 8.3) kJ mol-1(2.303RT)-1; r = 0.9960 The derived kinetic and thermodynamic parameters for benzyl chloroformate decomposition indicate the reaction proceeds through a concerted four-membered cyclic transition state to give benzyl chloride and CO2 gas. Neopentyl chloroformate undergoes a parallel reaction, where neopentyl chloride formation may arise from a polar-concerted four-membered cyclic transition state, whereas the mixture of olefins, 2-methyl-2-butene, and 2-methyl-1-butene appears to be produced from a carbene intermediate. This intermediate seems to be originated from a concerted five-membered cyclic transition state of the neopentyl substrate.
