Stereospecific Synthesis ofsec- andtert-Alkyl Azides from Alcohols and Trimethylsilyl Azide by a New Type of Oxidation–Reduction Condensation Using Phenyl Diphenylphosphinite and Trimethylsilylmethyl Azide
Mitsunobu Approach to the Synthesis of Optically Active α,α-Disubstituted Amino Acids
作者:Jonathan E. Green、David M. Bender、Stona Jackson、Martin J. O’Donnell、James R. McCarthy
DOI:10.1021/ol802325h
日期:2009.2.19
α-azido esters by Mitsunobureaction with HN3. Optimization of this reaction was shown to proceed at room temperature with high chemical yield using 1,1-(azodicarbonyl)dipiperidine (ADDP) and trimethylphosphine (PMe3). Complete inversion of configuration was observed at the α-carbon. Several α,α-disubstituted amino acids were synthesized in high overall chemical yield and optical purity.
A convenient two-step procedure for the construction of sulfur-containing quaternary centers from tert-alcohols involving chiral ones is established. tert-Alkyl diphenylphosphinites 1 were easily prepared in excellent yields from tert-alcohols and ClPPh2 by the combined use of Et3N and a catalytic amount of DMAP. Subsequent condensation of 1 with thiol 3 smoothly proceeded in the presence of quinone 2d to afford the corresponding tert-alkyl sulfides 4 in good to high yields via SN2 displacement. Removal of benzothiazol-2-yl group of (R)-4j was achieved with LiAlH4 to afford the desired chiral thiol (R)-5 in high yield.
Preparation of alkyl aryl sulfides from alcohols and arenethiols such as 2-sulfanyl-1,3-benzothiazole (BtzSH) is described by a new type of oxidation–reduction condensation using phenyl diphenylpho...
A new method for the Cu(OAc)2-catalyzed phenylation of tertiaryalcohols under mild basic conditions is described. Triphenylbismuth(V) diacetate and tetraphenylbismuth reagents undergo cross-coupli...
Stereospecific Synthesis of Alkyl Aryl Sulfides from Alcohols and 2-Sulfanylbenzothiazole Using Aryl Diphenylphosphinite and Azide Compounds by a New Type of Oxidation–Reduction Condensation
The preparation of alkylaryl sulfides from alcohols and 2-sulfanylbenzothiazole using phenyl diphenylphosphinite and azide compounds by a new type of oxidation–reduction condensation is described....