作者:Marcin Ptaszek、Brian E. McDowell、Jonathan S. Lindsey
DOI:10.1021/jo060119b
日期:2006.5.1
1-Formyldipyrromethanes are versatile precursors to porphyrins and chlorins. Two methods of synthesis of 1-formyl-dipyrromethanes have been investigated: (1) Vilsmeier formylation followed by selective removal of the unwanted 1,9-diformyldipyrromethane by dialkyltin complexation and (2) reaction with mesitylmagnesium bromide (MesMgBr) followed by formylation with phenyl formate. The two approaches are complementary (acidic versus basic conditions; statistical versus selective formylation). The latter was found to be more efficient for the preparation of 1-formyl-dipyrromethanes.
O-Alkyl S-(Pyridin-2-yl)carbonothiolates: Operationally Simple and Highly Nitrogen-Selective Reagents for Alkoxy Carbonylation of Amino Groups
Amino groups are selectively protected in good yields by reaction with O-alkyl S-(pyridin-2-yl)carbonothiolates in an appropriate solvent at room temperature in air. Even glucosamine, which contains multiple hydroxyl groups, is selectively N-protected in methanol.
通过与 O-烷基 S-(吡啶-2-基)碳硫醇盐在适当的溶剂中在室温下在空气中反应,氨基以良好的产率被选择性地保护。甚至含有多个羟基的葡糖胺也在甲醇中被选择性地 N 保护。
Conversion of Hydroxyl Groups in Alcohols to Other Functional Groups with<i>N</i>-Hydroxy-2-thiopyridone, and Its Application to Dialkylamines and Thiols
作者:Hideo Togo、Misa Fujii、Masataka Yokoyama
DOI:10.1246/bcsj.64.57
日期:1991.1
The radical decarboxylation reaction of N-alkoxyoxalyloxy-2-thiopyridone which was prepared by the reaction of alcohol, oxalyl chloride, and N-hydroxy-2-thiopyridone was studied both in the absence and presence of olefinic compounds. The same reactions with olefinic and acetylenic alcohols gave the corresponding lactone derivatives. On the other hand the unsymmetrical alkyl 2-pyridyl disulfides were obtained by the same reaction with aliphatic thiols.