Silica gel-mediated rearrangement of allylic acetates. Application to the synthesis of 1,3-enynes.
نویسندگان
چکیده
Silica gel was found to efficiently promote the rearrangement of allylic acetates into their most stable regioisomers under microwave irradiation. The reaction is easy to perform and eco-friendly. This method was applied to the metal-free synthesis of 1,3-enynes.
منابع مشابه
Titanium-mediated reductive cross-coupling reactions of imines with terminal alkynes: An efficient route for the synthesis of stereodefined allylic amines
Low-valency titanium species, generated in situ by using Ti(OiPr)4/2 c-C5H9MgCl reagent, react with imines to give a titanium-imine complex that can couple with terminal alkynes to provide azatitanacyclopentenes with excellent regioselectivity. Stereodefined allylic amines are obtained in good yields after hydrolysis or iodonolysis of the corresponding azatitanacyclopentenes. When ethynylcyclop...
متن کاملStudies on beta-lactam antibiotics. II. Synthesis and antibacterial activity of cephalosporins with substituted 1,3-dithietane directly attached to the C-3 position.
Preparation of cephalosporins bearing a 1,3-dithietane ring attached to the C-3 position using intramolecular rearrangement are described. The diastereoisomers (6a-I and 6a-II) were separated by silica gel column chromatography. These 3-[4-(carbamoyl carboxymethylene)-1,3-dithietane-2-yl]cephems showed comparable activity against Gram-negative bacteria to that of ceftazidime.
متن کاملDomino gold-catalyzed rearrangement and fluorination of propargyl acetates.
A combination of IPrAuNTf(2) as catalyst in the presence of Selectfluor has been successfully used for the high yielding synthesis of α-fluoroenones via 1,3-acyloxy rearrangement of propargyl acetates followed by Csp(2)-F bond formation, likely involving a redox Au(I)/Au(III) catalytic cycle.
متن کاملStereocontrolled synthesis of 1,5-stereogenic centers through three-carbon homologation of boronic esters.
Allylic pinacol boronic esters are stable toward 1,3-borotropic rearrangement. We developed a Pd(II)-mediated isomerization process that gives di- or trisubstituted allylic boronic esters with high E selectivity. The combination of this method with lithiation-borylation enables the synthesis of carbon chains that bear 1,5-stereogenic centers. The utility of this method has been demonstrated in ...
متن کاملPlatinum- and gold-catalyzed cycloisomerization reactions of hydroxylated enynes.
Exposure of enynes containing a hydroxyl group at one of the propargylic positions to catalytic amounts of either PtCl2 or (PPh3)AuCl/AgSbF6 results in a selective rearrangement with formation of bicyclo[3.1.0]hexan-3-one derivatives. The same products are obtained by a "one-pot" process on treatment of an alkynal with allylchlorodimethylsilane (4) and PtCl2 via a reaction cascade involving an ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Chemical communications
دوره 46 23 شماره
صفحات -
تاریخ انتشار 2010